xref: /aosp_15_r20/external/cronet/third_party/boringssl/src/include/openssl/ssl.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 /* Copyright (C) 1995-1998 Eric Young ([email protected])
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young ([email protected]).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson ([email protected]).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young ([email protected])"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson ([email protected])"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.]
56  */
57 /* ====================================================================
58  * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
59  *
60  * Redistribution and use in source and binary forms, with or without
61  * modification, are permitted provided that the following conditions
62  * are met:
63  *
64  * 1. Redistributions of source code must retain the above copyright
65  *    notice, this list of conditions and the following disclaimer.
66  *
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in
69  *    the documentation and/or other materials provided with the
70  *    distribution.
71  *
72  * 3. All advertising materials mentioning features or use of this
73  *    software must display the following acknowledgment:
74  *    "This product includes software developed by the OpenSSL Project
75  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
76  *
77  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
78  *    endorse or promote products derived from this software without
79  *    prior written permission. For written permission, please contact
80  *    [email protected].
81  *
82  * 5. Products derived from this software may not be called "OpenSSL"
83  *    nor may "OpenSSL" appear in their names without prior written
84  *    permission of the OpenSSL Project.
85  *
86  * 6. Redistributions of any form whatsoever must retain the following
87  *    acknowledgment:
88  *    "This product includes software developed by the OpenSSL Project
89  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
90  *
91  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
92  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
95  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
96  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
97  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
98  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
99  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
100  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
101  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
102  * OF THE POSSIBILITY OF SUCH DAMAGE.
103  * ====================================================================
104  *
105  * This product includes cryptographic software written by Eric Young
106  * ([email protected]).  This product includes software written by Tim
107  * Hudson ([email protected]).
108  *
109  */
110 /* ====================================================================
111  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
112  * ECC cipher suite support in OpenSSL originally developed by
113  * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
114  */
115 /* ====================================================================
116  * Copyright 2005 Nokia. All rights reserved.
117  *
118  * The portions of the attached software ("Contribution") is developed by
119  * Nokia Corporation and is licensed pursuant to the OpenSSL open source
120  * license.
121  *
122  * The Contribution, originally written by Mika Kousa and Pasi Eronen of
123  * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
124  * support (see RFC 4279) to OpenSSL.
125  *
126  * No patent licenses or other rights except those expressly stated in
127  * the OpenSSL open source license shall be deemed granted or received
128  * expressly, by implication, estoppel, or otherwise.
129  *
130  * No assurances are provided by Nokia that the Contribution does not
131  * infringe the patent or other intellectual property rights of any third
132  * party or that the license provides you with all the necessary rights
133  * to make use of the Contribution.
134  *
135  * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
136  * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
137  * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
138  * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
139  * OTHERWISE.
140  */
141 
142 #ifndef OPENSSL_HEADER_SSL_H
143 #define OPENSSL_HEADER_SSL_H
144 
145 #include <openssl/base.h>
146 
147 #include <openssl/bio.h>
148 #include <openssl/buf.h>
149 #include <openssl/pem.h>
150 #include <openssl/span.h>
151 #include <openssl/ssl3.h>
152 #include <openssl/thread.h>
153 #include <openssl/tls1.h>
154 #include <openssl/x509.h>
155 
156 #if !defined(OPENSSL_WINDOWS)
157 #include <sys/time.h>
158 #endif
159 
160 // Forward-declare struct timeval. On Windows, it is defined in winsock2.h and
161 // Windows headers define too many macros to be included in public headers.
162 // However, only a forward declaration is needed.
163 struct timeval;
164 
165 #if defined(__cplusplus)
166 extern "C" {
167 #endif
168 
169 
170 // SSL implementation.
171 
172 
173 // SSL contexts.
174 //
175 // |SSL_CTX| objects manage shared state and configuration between multiple TLS
176 // or DTLS connections. Whether the connections are TLS or DTLS is selected by
177 // an |SSL_METHOD| on creation.
178 //
179 // |SSL_CTX| are reference-counted and may be shared by connections across
180 // multiple threads. Once shared, functions which change the |SSL_CTX|'s
181 // configuration may not be used.
182 
183 // TLS_method is the |SSL_METHOD| used for TLS connections.
184 OPENSSL_EXPORT const SSL_METHOD *TLS_method(void);
185 
186 // DTLS_method is the |SSL_METHOD| used for DTLS connections.
187 OPENSSL_EXPORT const SSL_METHOD *DTLS_method(void);
188 
189 // TLS_with_buffers_method is like |TLS_method|, but avoids all use of
190 // crypto/x509. All client connections created with |TLS_with_buffers_method|
191 // will fail unless a certificate verifier is installed with
192 // |SSL_set_custom_verify| or |SSL_CTX_set_custom_verify|.
193 OPENSSL_EXPORT const SSL_METHOD *TLS_with_buffers_method(void);
194 
195 // DTLS_with_buffers_method is like |DTLS_method|, but avoids all use of
196 // crypto/x509.
197 OPENSSL_EXPORT const SSL_METHOD *DTLS_with_buffers_method(void);
198 
199 // SSL_CTX_new returns a newly-allocated |SSL_CTX| with default settings or NULL
200 // on error.
201 OPENSSL_EXPORT SSL_CTX *SSL_CTX_new(const SSL_METHOD *method);
202 
203 // SSL_CTX_up_ref increments the reference count of |ctx|. It returns one.
204 OPENSSL_EXPORT int SSL_CTX_up_ref(SSL_CTX *ctx);
205 
206 // SSL_CTX_free releases memory associated with |ctx|.
207 OPENSSL_EXPORT void SSL_CTX_free(SSL_CTX *ctx);
208 
209 
210 // SSL connections.
211 //
212 // An |SSL| object represents a single TLS or DTLS connection. Although the
213 // shared |SSL_CTX| is thread-safe, an |SSL| is not thread-safe and may only be
214 // used on one thread at a time.
215 
216 // SSL_new returns a newly-allocated |SSL| using |ctx| or NULL on error. The new
217 // connection inherits settings from |ctx| at the time of creation. Settings may
218 // also be individually configured on the connection.
219 //
220 // On creation, an |SSL| is not configured to be either a client or server. Call
221 // |SSL_set_connect_state| or |SSL_set_accept_state| to set this.
222 OPENSSL_EXPORT SSL *SSL_new(SSL_CTX *ctx);
223 
224 // SSL_free releases memory associated with |ssl|.
225 OPENSSL_EXPORT void SSL_free(SSL *ssl);
226 
227 // SSL_get_SSL_CTX returns the |SSL_CTX| associated with |ssl|. If
228 // |SSL_set_SSL_CTX| is called, it returns the new |SSL_CTX|, not the initial
229 // one.
230 OPENSSL_EXPORT SSL_CTX *SSL_get_SSL_CTX(const SSL *ssl);
231 
232 // SSL_set_connect_state configures |ssl| to be a client.
233 OPENSSL_EXPORT void SSL_set_connect_state(SSL *ssl);
234 
235 // SSL_set_accept_state configures |ssl| to be a server.
236 OPENSSL_EXPORT void SSL_set_accept_state(SSL *ssl);
237 
238 // SSL_is_server returns one if |ssl| is configured as a server and zero
239 // otherwise.
240 OPENSSL_EXPORT int SSL_is_server(const SSL *ssl);
241 
242 // SSL_is_dtls returns one if |ssl| is a DTLS connection and zero otherwise.
243 OPENSSL_EXPORT int SSL_is_dtls(const SSL *ssl);
244 
245 // SSL_set_bio configures |ssl| to read from |rbio| and write to |wbio|. |ssl|
246 // takes ownership of the two |BIO|s. If |rbio| and |wbio| are the same, |ssl|
247 // only takes ownership of one reference.
248 //
249 // In DTLS, |rbio| must be non-blocking to properly handle timeouts and
250 // retransmits.
251 //
252 // If |rbio| is the same as the currently configured |BIO| for reading, that
253 // side is left untouched and is not freed.
254 //
255 // If |wbio| is the same as the currently configured |BIO| for writing AND |ssl|
256 // is not currently configured to read from and write to the same |BIO|, that
257 // side is left untouched and is not freed. This asymmetry is present for
258 // historical reasons.
259 //
260 // Due to the very complex historical behavior of this function, calling this
261 // function if |ssl| already has |BIO|s configured is deprecated. Prefer
262 // |SSL_set0_rbio| and |SSL_set0_wbio| instead.
263 OPENSSL_EXPORT void SSL_set_bio(SSL *ssl, BIO *rbio, BIO *wbio);
264 
265 // SSL_set0_rbio configures |ssl| to read from |rbio|. It takes ownership of
266 // |rbio|.
267 //
268 // Note that, although this function and |SSL_set0_wbio| may be called on the
269 // same |BIO|, each call takes a reference. Use |BIO_up_ref| to balance this.
270 OPENSSL_EXPORT void SSL_set0_rbio(SSL *ssl, BIO *rbio);
271 
272 // SSL_set0_wbio configures |ssl| to write to |wbio|. It takes ownership of
273 // |wbio|.
274 //
275 // Note that, although this function and |SSL_set0_rbio| may be called on the
276 // same |BIO|, each call takes a reference. Use |BIO_up_ref| to balance this.
277 OPENSSL_EXPORT void SSL_set0_wbio(SSL *ssl, BIO *wbio);
278 
279 // SSL_get_rbio returns the |BIO| that |ssl| reads from.
280 OPENSSL_EXPORT BIO *SSL_get_rbio(const SSL *ssl);
281 
282 // SSL_get_wbio returns the |BIO| that |ssl| writes to.
283 OPENSSL_EXPORT BIO *SSL_get_wbio(const SSL *ssl);
284 
285 // SSL_get_fd calls |SSL_get_rfd|.
286 OPENSSL_EXPORT int SSL_get_fd(const SSL *ssl);
287 
288 // SSL_get_rfd returns the file descriptor that |ssl| is configured to read
289 // from. If |ssl|'s read |BIO| is not configured or doesn't wrap a file
290 // descriptor then it returns -1.
291 //
292 // Note: On Windows, this may return either a file descriptor or a socket (cast
293 // to int), depending on whether |ssl| was configured with a file descriptor or
294 // socket |BIO|.
295 OPENSSL_EXPORT int SSL_get_rfd(const SSL *ssl);
296 
297 // SSL_get_wfd returns the file descriptor that |ssl| is configured to write
298 // to. If |ssl|'s write |BIO| is not configured or doesn't wrap a file
299 // descriptor then it returns -1.
300 //
301 // Note: On Windows, this may return either a file descriptor or a socket (cast
302 // to int), depending on whether |ssl| was configured with a file descriptor or
303 // socket |BIO|.
304 OPENSSL_EXPORT int SSL_get_wfd(const SSL *ssl);
305 
306 #if !defined(OPENSSL_NO_SOCK)
307 // SSL_set_fd configures |ssl| to read from and write to |fd|. It returns one
308 // on success and zero on allocation error. The caller retains ownership of
309 // |fd|.
310 //
311 // On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
312 OPENSSL_EXPORT int SSL_set_fd(SSL *ssl, int fd);
313 
314 // SSL_set_rfd configures |ssl| to read from |fd|. It returns one on success and
315 // zero on allocation error. The caller retains ownership of |fd|.
316 //
317 // On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
318 OPENSSL_EXPORT int SSL_set_rfd(SSL *ssl, int fd);
319 
320 // SSL_set_wfd configures |ssl| to write to |fd|. It returns one on success and
321 // zero on allocation error. The caller retains ownership of |fd|.
322 //
323 // On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
324 OPENSSL_EXPORT int SSL_set_wfd(SSL *ssl, int fd);
325 #endif  // !OPENSSL_NO_SOCK
326 
327 // SSL_do_handshake continues the current handshake. If there is none or the
328 // handshake has completed or False Started, it returns one. Otherwise, it
329 // returns <= 0. The caller should pass the value into |SSL_get_error| to
330 // determine how to proceed.
331 //
332 // In DTLS, the caller must drive retransmissions. Whenever |SSL_get_error|
333 // signals |SSL_ERROR_WANT_READ|, use |DTLSv1_get_timeout| to determine the
334 // current timeout. If it expires before the next retry, call
335 // |DTLSv1_handle_timeout|. Note that DTLS handshake retransmissions use fresh
336 // sequence numbers, so it is not sufficient to replay packets at the transport.
337 //
338 // TODO(davidben): Ensure 0 is only returned on transport EOF.
339 // https://crbug.com/466303.
340 OPENSSL_EXPORT int SSL_do_handshake(SSL *ssl);
341 
342 // SSL_connect configures |ssl| as a client, if unconfigured, and calls
343 // |SSL_do_handshake|.
344 OPENSSL_EXPORT int SSL_connect(SSL *ssl);
345 
346 // SSL_accept configures |ssl| as a server, if unconfigured, and calls
347 // |SSL_do_handshake|.
348 OPENSSL_EXPORT int SSL_accept(SSL *ssl);
349 
350 // SSL_read reads up to |num| bytes from |ssl| into |buf|. It implicitly runs
351 // any pending handshakes, including renegotiations when enabled. On success, it
352 // returns the number of bytes read. Otherwise, it returns <= 0. The caller
353 // should pass the value into |SSL_get_error| to determine how to proceed.
354 //
355 // TODO(davidben): Ensure 0 is only returned on transport EOF.
356 // https://crbug.com/466303.
357 OPENSSL_EXPORT int SSL_read(SSL *ssl, void *buf, int num);
358 
359 // SSL_peek behaves like |SSL_read| but does not consume any bytes returned.
360 OPENSSL_EXPORT int SSL_peek(SSL *ssl, void *buf, int num);
361 
362 // SSL_pending returns the number of buffered, decrypted bytes available for
363 // read in |ssl|. It does not read from the transport.
364 //
365 // In DTLS, it is possible for this function to return zero while there is
366 // buffered, undecrypted data from the transport in |ssl|. For example,
367 // |SSL_read| may read a datagram with two records, decrypt the first, and leave
368 // the second buffered for a subsequent call to |SSL_read|. Callers that wish to
369 // detect this case can use |SSL_has_pending|.
370 OPENSSL_EXPORT int SSL_pending(const SSL *ssl);
371 
372 // SSL_has_pending returns one if |ssl| has buffered, decrypted bytes available
373 // for read, or if |ssl| has buffered data from the transport that has not yet
374 // been decrypted. If |ssl| has neither, this function returns zero.
375 //
376 // In TLS, BoringSSL does not implement read-ahead, so this function returns one
377 // if and only if |SSL_pending| would return a non-zero value. In DTLS, it is
378 // possible for this function to return one while |SSL_pending| returns zero.
379 // For example, |SSL_read| may read a datagram with two records, decrypt the
380 // first, and leave the second buffered for a subsequent call to |SSL_read|.
381 //
382 // As a result, if this function returns one, the next call to |SSL_read| may
383 // still fail, read from the transport, or both. The buffered, undecrypted data
384 // may be invalid or incomplete.
385 OPENSSL_EXPORT int SSL_has_pending(const SSL *ssl);
386 
387 // SSL_write writes up to |num| bytes from |buf| into |ssl|. It implicitly runs
388 // any pending handshakes, including renegotiations when enabled. On success, it
389 // returns the number of bytes written. Otherwise, it returns <= 0. The caller
390 // should pass the value into |SSL_get_error| to determine how to proceed.
391 //
392 // In TLS, a non-blocking |SSL_write| differs from non-blocking |write| in that
393 // a failed |SSL_write| still commits to the data passed in. When retrying, the
394 // caller must supply the original write buffer (or a larger one containing the
395 // original as a prefix). By default, retries will fail if they also do not
396 // reuse the same |buf| pointer. This may be relaxed with
397 // |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER|, but the buffer contents still must be
398 // unchanged.
399 //
400 // By default, in TLS, |SSL_write| will not return success until all |num| bytes
401 // are written. This may be relaxed with |SSL_MODE_ENABLE_PARTIAL_WRITE|. It
402 // allows |SSL_write| to complete with a partial result when only part of the
403 // input was written in a single record.
404 //
405 // In DTLS, neither |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER| and
406 // |SSL_MODE_ENABLE_PARTIAL_WRITE| do anything. The caller may retry with a
407 // different buffer freely. A single call to |SSL_write| only ever writes a
408 // single record in a single packet, so |num| must be at most
409 // |SSL3_RT_MAX_PLAIN_LENGTH|.
410 //
411 // TODO(davidben): Ensure 0 is only returned on transport EOF.
412 // https://crbug.com/466303.
413 OPENSSL_EXPORT int SSL_write(SSL *ssl, const void *buf, int num);
414 
415 // SSL_KEY_UPDATE_REQUESTED indicates that the peer should reply to a KeyUpdate
416 // message with its own, thus updating traffic secrets for both directions on
417 // the connection.
418 #define SSL_KEY_UPDATE_REQUESTED 1
419 
420 // SSL_KEY_UPDATE_NOT_REQUESTED indicates that the peer should not reply with
421 // it's own KeyUpdate message.
422 #define SSL_KEY_UPDATE_NOT_REQUESTED 0
423 
424 // SSL_key_update queues a TLS 1.3 KeyUpdate message to be sent on |ssl|
425 // if one is not already queued. The |request_type| argument must one of the
426 // |SSL_KEY_UPDATE_*| values. This function requires that |ssl| have completed a
427 // TLS >= 1.3 handshake. It returns one on success or zero on error.
428 //
429 // Note that this function does not _send_ the message itself. The next call to
430 // |SSL_write| will cause the message to be sent. |SSL_write| may be called with
431 // a zero length to flush a KeyUpdate message when no application data is
432 // pending.
433 OPENSSL_EXPORT int SSL_key_update(SSL *ssl, int request_type);
434 
435 // SSL_shutdown shuts down |ssl|. It runs in two stages. First, it sends
436 // close_notify and returns zero or one on success or -1 on failure. Zero
437 // indicates that close_notify was sent, but not received, and one additionally
438 // indicates that the peer's close_notify had already been received.
439 //
440 // To then wait for the peer's close_notify, run |SSL_shutdown| to completion a
441 // second time. This returns 1 on success and -1 on failure. Application data
442 // is considered a fatal error at this point. To process or discard it, read
443 // until close_notify with |SSL_read| instead.
444 //
445 // In both cases, on failure, pass the return value into |SSL_get_error| to
446 // determine how to proceed.
447 //
448 // Most callers should stop at the first stage. Reading for close_notify is
449 // primarily used for uncommon protocols where the underlying transport is
450 // reused after TLS completes. Additionally, DTLS uses an unordered transport
451 // and is unordered, so the second stage is a no-op in DTLS.
452 OPENSSL_EXPORT int SSL_shutdown(SSL *ssl);
453 
454 // SSL_CTX_set_quiet_shutdown sets quiet shutdown on |ctx| to |mode|. If
455 // enabled, |SSL_shutdown| will not send a close_notify alert or wait for one
456 // from the peer. It will instead synchronously return one.
457 OPENSSL_EXPORT void SSL_CTX_set_quiet_shutdown(SSL_CTX *ctx, int mode);
458 
459 // SSL_CTX_get_quiet_shutdown returns whether quiet shutdown is enabled for
460 // |ctx|.
461 OPENSSL_EXPORT int SSL_CTX_get_quiet_shutdown(const SSL_CTX *ctx);
462 
463 // SSL_set_quiet_shutdown sets quiet shutdown on |ssl| to |mode|. If enabled,
464 // |SSL_shutdown| will not send a close_notify alert or wait for one from the
465 // peer. It will instead synchronously return one.
466 OPENSSL_EXPORT void SSL_set_quiet_shutdown(SSL *ssl, int mode);
467 
468 // SSL_get_quiet_shutdown returns whether quiet shutdown is enabled for
469 // |ssl|.
470 OPENSSL_EXPORT int SSL_get_quiet_shutdown(const SSL *ssl);
471 
472 // SSL_get_error returns a |SSL_ERROR_*| value for the most recent operation on
473 // |ssl|. It should be called after an operation failed to determine whether the
474 // error was fatal and, if not, when to retry.
475 OPENSSL_EXPORT int SSL_get_error(const SSL *ssl, int ret_code);
476 
477 // SSL_ERROR_NONE indicates the operation succeeded.
478 #define SSL_ERROR_NONE 0
479 
480 // SSL_ERROR_SSL indicates the operation failed within the library. The caller
481 // may inspect the error queue for more information.
482 #define SSL_ERROR_SSL 1
483 
484 // SSL_ERROR_WANT_READ indicates the operation failed attempting to read from
485 // the transport. The caller may retry the operation when the transport is ready
486 // for reading.
487 //
488 // If signaled by a DTLS handshake, the caller must also call
489 // |DTLSv1_get_timeout| and |DTLSv1_handle_timeout| as appropriate. See
490 // |SSL_do_handshake|.
491 #define SSL_ERROR_WANT_READ 2
492 
493 // SSL_ERROR_WANT_WRITE indicates the operation failed attempting to write to
494 // the transport. The caller may retry the operation when the transport is ready
495 // for writing.
496 #define SSL_ERROR_WANT_WRITE 3
497 
498 // SSL_ERROR_WANT_X509_LOOKUP indicates the operation failed in calling the
499 // |cert_cb| or |client_cert_cb|. The caller may retry the operation when the
500 // callback is ready to return a certificate or one has been configured
501 // externally.
502 //
503 // See also |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb|.
504 #define SSL_ERROR_WANT_X509_LOOKUP 4
505 
506 // SSL_ERROR_SYSCALL indicates the operation failed externally to the library.
507 // The caller should consult the system-specific error mechanism. This is
508 // typically |errno| but may be something custom if using a custom |BIO|. It
509 // may also be signaled if the transport returned EOF, in which case the
510 // operation's return value will be zero.
511 #define SSL_ERROR_SYSCALL 5
512 
513 // SSL_ERROR_ZERO_RETURN indicates the operation failed because the connection
514 // was cleanly shut down with a close_notify alert.
515 #define SSL_ERROR_ZERO_RETURN 6
516 
517 // SSL_ERROR_WANT_CONNECT indicates the operation failed attempting to connect
518 // the transport (the |BIO| signaled |BIO_RR_CONNECT|). The caller may retry the
519 // operation when the transport is ready.
520 #define SSL_ERROR_WANT_CONNECT 7
521 
522 // SSL_ERROR_WANT_ACCEPT indicates the operation failed attempting to accept a
523 // connection from the transport (the |BIO| signaled |BIO_RR_ACCEPT|). The
524 // caller may retry the operation when the transport is ready.
525 //
526 // TODO(davidben): Remove this. It's used by accept BIOs which are bizarre.
527 #define SSL_ERROR_WANT_ACCEPT 8
528 
529 // SSL_ERROR_WANT_CHANNEL_ID_LOOKUP is never used.
530 //
531 // TODO(davidben): Remove this. Some callers reference it when stringifying
532 // errors. They should use |SSL_error_description| instead.
533 #define SSL_ERROR_WANT_CHANNEL_ID_LOOKUP 9
534 
535 // SSL_ERROR_PENDING_SESSION indicates the operation failed because the session
536 // lookup callback indicated the session was unavailable. The caller may retry
537 // the operation when lookup has completed.
538 //
539 // See also |SSL_CTX_sess_set_get_cb| and |SSL_magic_pending_session_ptr|.
540 #define SSL_ERROR_PENDING_SESSION 11
541 
542 // SSL_ERROR_PENDING_CERTIFICATE indicates the operation failed because the
543 // early callback indicated certificate lookup was incomplete. The caller may
544 // retry the operation when lookup has completed.
545 //
546 // See also |SSL_CTX_set_select_certificate_cb|.
547 #define SSL_ERROR_PENDING_CERTIFICATE 12
548 
549 // SSL_ERROR_WANT_PRIVATE_KEY_OPERATION indicates the operation failed because
550 // a private key operation was unfinished. The caller may retry the operation
551 // when the private key operation is complete.
552 //
553 // See also |SSL_set_private_key_method|, |SSL_CTX_set_private_key_method|, and
554 // |SSL_CREDENTIAL_set_private_key_method|.
555 #define SSL_ERROR_WANT_PRIVATE_KEY_OPERATION 13
556 
557 // SSL_ERROR_PENDING_TICKET indicates that a ticket decryption is pending. The
558 // caller may retry the operation when the decryption is ready.
559 //
560 // See also |SSL_CTX_set_ticket_aead_method|.
561 #define SSL_ERROR_PENDING_TICKET 14
562 
563 // SSL_ERROR_EARLY_DATA_REJECTED indicates that early data was rejected. The
564 // caller should treat this as a connection failure and retry any operations
565 // associated with the rejected early data. |SSL_reset_early_data_reject| may be
566 // used to reuse the underlying connection for the retry.
567 #define SSL_ERROR_EARLY_DATA_REJECTED 15
568 
569 // SSL_ERROR_WANT_CERTIFICATE_VERIFY indicates the operation failed because
570 // certificate verification was incomplete. The caller may retry the operation
571 // when certificate verification is complete.
572 //
573 // See also |SSL_CTX_set_custom_verify|.
574 #define SSL_ERROR_WANT_CERTIFICATE_VERIFY 16
575 
576 #define SSL_ERROR_HANDOFF 17
577 #define SSL_ERROR_HANDBACK 18
578 
579 // SSL_ERROR_WANT_RENEGOTIATE indicates the operation is pending a response to
580 // a renegotiation request from the server. The caller may call
581 // |SSL_renegotiate| to schedule a renegotiation and retry the operation.
582 //
583 // See also |ssl_renegotiate_explicit|.
584 #define SSL_ERROR_WANT_RENEGOTIATE 19
585 
586 // SSL_ERROR_HANDSHAKE_HINTS_READY indicates the handshake has progressed enough
587 // for |SSL_serialize_handshake_hints| to be called. See also
588 // |SSL_request_handshake_hints|.
589 #define SSL_ERROR_HANDSHAKE_HINTS_READY 20
590 
591 // SSL_error_description returns a string representation of |err|, where |err|
592 // is one of the |SSL_ERROR_*| constants returned by |SSL_get_error|, or NULL
593 // if the value is unrecognized.
594 OPENSSL_EXPORT const char *SSL_error_description(int err);
595 
596 // SSL_set_mtu sets the |ssl|'s MTU in DTLS to |mtu|. It returns one on success
597 // and zero on failure.
598 OPENSSL_EXPORT int SSL_set_mtu(SSL *ssl, unsigned mtu);
599 
600 // DTLSv1_set_initial_timeout_duration sets the initial duration for a DTLS
601 // handshake timeout.
602 //
603 // This duration overrides the default of 1 second, which is the strong
604 // recommendation of RFC 6347 (see section 4.2.4.1). However, there may exist
605 // situations where a shorter timeout would be beneficial, such as for
606 // time-sensitive applications.
607 OPENSSL_EXPORT void DTLSv1_set_initial_timeout_duration(SSL *ssl,
608                                                         unsigned duration_ms);
609 
610 // DTLSv1_get_timeout queries the next DTLS handshake timeout. If there is a
611 // timeout in progress, it sets |*out| to the time remaining and returns one.
612 // Otherwise, it returns zero.
613 //
614 // When the timeout expires, call |DTLSv1_handle_timeout| to handle the
615 // retransmit behavior.
616 //
617 // NOTE: This function must be queried again whenever the handshake state
618 // machine changes, including when |DTLSv1_handle_timeout| is called.
619 OPENSSL_EXPORT int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out);
620 
621 // DTLSv1_handle_timeout is called when a DTLS handshake timeout expires. If no
622 // timeout had expired, it returns 0. Otherwise, it retransmits the previous
623 // flight of handshake messages and returns 1. If too many timeouts had expired
624 // without progress or an error occurs, it returns -1.
625 //
626 // The caller's external timer should be compatible with the one |ssl| queries
627 // within some fudge factor. Otherwise, the call will be a no-op, but
628 // |DTLSv1_get_timeout| will return an updated timeout.
629 //
630 // If the function returns -1, checking if |SSL_get_error| returns
631 // |SSL_ERROR_WANT_WRITE| may be used to determine if the retransmit failed due
632 // to a non-fatal error at the write |BIO|. However, the operation may not be
633 // retried until the next timeout fires.
634 //
635 // WARNING: This function breaks the usual return value convention.
636 //
637 // TODO(davidben): This |SSL_ERROR_WANT_WRITE| behavior is kind of bizarre.
638 OPENSSL_EXPORT int DTLSv1_handle_timeout(SSL *ssl);
639 
640 
641 // Protocol versions.
642 
643 #define DTLS1_VERSION_MAJOR 0xfe
644 #define SSL3_VERSION_MAJOR 0x03
645 
646 #define SSL3_VERSION 0x0300
647 #define TLS1_VERSION 0x0301
648 #define TLS1_1_VERSION 0x0302
649 #define TLS1_2_VERSION 0x0303
650 #define TLS1_3_VERSION 0x0304
651 
652 #define DTLS1_VERSION 0xfeff
653 #define DTLS1_2_VERSION 0xfefd
654 
655 // SSL_CTX_set_min_proto_version sets the minimum protocol version for |ctx| to
656 // |version|. If |version| is zero, the default minimum version is used. It
657 // returns one on success and zero if |version| is invalid.
658 OPENSSL_EXPORT int SSL_CTX_set_min_proto_version(SSL_CTX *ctx,
659                                                  uint16_t version);
660 
661 // SSL_CTX_set_max_proto_version sets the maximum protocol version for |ctx| to
662 // |version|. If |version| is zero, the default maximum version is used. It
663 // returns one on success and zero if |version| is invalid.
664 OPENSSL_EXPORT int SSL_CTX_set_max_proto_version(SSL_CTX *ctx,
665                                                  uint16_t version);
666 
667 // SSL_CTX_get_min_proto_version returns the minimum protocol version for |ctx|
668 OPENSSL_EXPORT uint16_t SSL_CTX_get_min_proto_version(const SSL_CTX *ctx);
669 
670 // SSL_CTX_get_max_proto_version returns the maximum protocol version for |ctx|
671 OPENSSL_EXPORT uint16_t SSL_CTX_get_max_proto_version(const SSL_CTX *ctx);
672 
673 // SSL_set_min_proto_version sets the minimum protocol version for |ssl| to
674 // |version|. If |version| is zero, the default minimum version is used. It
675 // returns one on success and zero if |version| is invalid.
676 OPENSSL_EXPORT int SSL_set_min_proto_version(SSL *ssl, uint16_t version);
677 
678 // SSL_set_max_proto_version sets the maximum protocol version for |ssl| to
679 // |version|. If |version| is zero, the default maximum version is used. It
680 // returns one on success and zero if |version| is invalid.
681 OPENSSL_EXPORT int SSL_set_max_proto_version(SSL *ssl, uint16_t version);
682 
683 // SSL_get_min_proto_version returns the minimum protocol version for |ssl|. If
684 // the connection's configuration has been shed, 0 is returned.
685 OPENSSL_EXPORT uint16_t SSL_get_min_proto_version(const SSL *ssl);
686 
687 // SSL_get_max_proto_version returns the maximum protocol version for |ssl|. If
688 // the connection's configuration has been shed, 0 is returned.
689 OPENSSL_EXPORT uint16_t SSL_get_max_proto_version(const SSL *ssl);
690 
691 // SSL_version returns the TLS or DTLS protocol version used by |ssl|, which is
692 // one of the |*_VERSION| values. (E.g. |TLS1_2_VERSION|.) Before the version
693 // is negotiated, the result is undefined.
694 OPENSSL_EXPORT int SSL_version(const SSL *ssl);
695 
696 
697 // Options.
698 //
699 // Options configure protocol behavior.
700 
701 // SSL_OP_NO_QUERY_MTU, in DTLS, disables querying the MTU from the underlying
702 // |BIO|. Instead, the MTU is configured with |SSL_set_mtu|.
703 #define SSL_OP_NO_QUERY_MTU 0x00001000L
704 
705 // SSL_OP_NO_TICKET disables session ticket support (RFC 5077).
706 #define SSL_OP_NO_TICKET 0x00004000L
707 
708 // SSL_OP_CIPHER_SERVER_PREFERENCE configures servers to select ciphers and
709 // ECDHE curves according to the server's preferences instead of the
710 // client's.
711 #define SSL_OP_CIPHER_SERVER_PREFERENCE 0x00400000L
712 
713 // The following flags toggle individual protocol versions. This is deprecated.
714 // Use |SSL_CTX_set_min_proto_version| and |SSL_CTX_set_max_proto_version|
715 // instead.
716 #define SSL_OP_NO_TLSv1 0x04000000L
717 #define SSL_OP_NO_TLSv1_2 0x08000000L
718 #define SSL_OP_NO_TLSv1_1 0x10000000L
719 #define SSL_OP_NO_TLSv1_3 0x20000000L
720 #define SSL_OP_NO_DTLSv1 SSL_OP_NO_TLSv1
721 #define SSL_OP_NO_DTLSv1_2 SSL_OP_NO_TLSv1_2
722 
723 // SSL_CTX_set_options enables all options set in |options| (which should be one
724 // or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
725 // bitmask representing the resulting enabled options.
726 OPENSSL_EXPORT uint32_t SSL_CTX_set_options(SSL_CTX *ctx, uint32_t options);
727 
728 // SSL_CTX_clear_options disables all options set in |options| (which should be
729 // one or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
730 // bitmask representing the resulting enabled options.
731 OPENSSL_EXPORT uint32_t SSL_CTX_clear_options(SSL_CTX *ctx, uint32_t options);
732 
733 // SSL_CTX_get_options returns a bitmask of |SSL_OP_*| values that represent all
734 // the options enabled for |ctx|.
735 OPENSSL_EXPORT uint32_t SSL_CTX_get_options(const SSL_CTX *ctx);
736 
737 // SSL_set_options enables all options set in |options| (which should be one or
738 // more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a bitmask
739 // representing the resulting enabled options.
740 OPENSSL_EXPORT uint32_t SSL_set_options(SSL *ssl, uint32_t options);
741 
742 // SSL_clear_options disables all options set in |options| (which should be one
743 // or more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a
744 // bitmask representing the resulting enabled options.
745 OPENSSL_EXPORT uint32_t SSL_clear_options(SSL *ssl, uint32_t options);
746 
747 // SSL_get_options returns a bitmask of |SSL_OP_*| values that represent all the
748 // options enabled for |ssl|.
749 OPENSSL_EXPORT uint32_t SSL_get_options(const SSL *ssl);
750 
751 
752 // Modes.
753 //
754 // Modes configure API behavior.
755 
756 // SSL_MODE_ENABLE_PARTIAL_WRITE, in TLS, allows |SSL_write| to complete with a
757 // partial result when the only part of the input was written in a single
758 // record. In DTLS, it does nothing.
759 #define SSL_MODE_ENABLE_PARTIAL_WRITE 0x00000001L
760 
761 // SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER, in TLS, allows retrying an incomplete
762 // |SSL_write| with a different buffer. However, |SSL_write| still assumes the
763 // buffer contents are unchanged. This is not the default to avoid the
764 // misconception that non-blocking |SSL_write| behaves like non-blocking
765 // |write|. In DTLS, it does nothing.
766 #define SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER 0x00000002L
767 
768 // SSL_MODE_NO_AUTO_CHAIN disables automatically building a certificate chain
769 // before sending certificates to the peer. This flag is set (and the feature
770 // disabled) by default.
771 // TODO(davidben): Remove this behavior. https://crbug.com/boringssl/42.
772 #define SSL_MODE_NO_AUTO_CHAIN 0x00000008L
773 
774 // SSL_MODE_ENABLE_FALSE_START allows clients to send application data before
775 // receipt of ChangeCipherSpec and Finished. This mode enables full handshakes
776 // to 'complete' in one RTT. See RFC 7918.
777 //
778 // When False Start is enabled, |SSL_do_handshake| may succeed before the
779 // handshake has completely finished. |SSL_write| will function at this point,
780 // and |SSL_read| will transparently wait for the final handshake leg before
781 // returning application data. To determine if False Start occurred or when the
782 // handshake is completely finished, see |SSL_in_false_start|, |SSL_in_init|,
783 // and |SSL_CB_HANDSHAKE_DONE| from |SSL_CTX_set_info_callback|.
784 #define SSL_MODE_ENABLE_FALSE_START 0x00000080L
785 
786 // SSL_MODE_CBC_RECORD_SPLITTING causes multi-byte CBC records in TLS 1.0 to be
787 // split in two: the first record will contain a single byte and the second will
788 // contain the remainder. This effectively randomises the IV and prevents BEAST
789 // attacks.
790 #define SSL_MODE_CBC_RECORD_SPLITTING 0x00000100L
791 
792 // SSL_MODE_NO_SESSION_CREATION will cause any attempts to create a session to
793 // fail with SSL_R_SESSION_MAY_NOT_BE_CREATED. This can be used to enforce that
794 // session resumption is used for a given SSL*.
795 #define SSL_MODE_NO_SESSION_CREATION 0x00000200L
796 
797 // SSL_MODE_SEND_FALLBACK_SCSV sends TLS_FALLBACK_SCSV in the ClientHello.
798 // To be set only by applications that reconnect with a downgraded protocol
799 // version; see RFC 7507 for details.
800 //
801 // DO NOT ENABLE THIS if your application attempts a normal handshake. Only use
802 // this in explicit fallback retries, following the guidance in RFC 7507.
803 #define SSL_MODE_SEND_FALLBACK_SCSV 0x00000400L
804 
805 // SSL_CTX_set_mode enables all modes set in |mode| (which should be one or more
806 // of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a bitmask
807 // representing the resulting enabled modes.
808 OPENSSL_EXPORT uint32_t SSL_CTX_set_mode(SSL_CTX *ctx, uint32_t mode);
809 
810 // SSL_CTX_clear_mode disables all modes set in |mode| (which should be one or
811 // more of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a
812 // bitmask representing the resulting enabled modes.
813 OPENSSL_EXPORT uint32_t SSL_CTX_clear_mode(SSL_CTX *ctx, uint32_t mode);
814 
815 // SSL_CTX_get_mode returns a bitmask of |SSL_MODE_*| values that represent all
816 // the modes enabled for |ssl|.
817 OPENSSL_EXPORT uint32_t SSL_CTX_get_mode(const SSL_CTX *ctx);
818 
819 // SSL_set_mode enables all modes set in |mode| (which should be one or more of
820 // the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
821 // representing the resulting enabled modes.
822 OPENSSL_EXPORT uint32_t SSL_set_mode(SSL *ssl, uint32_t mode);
823 
824 // SSL_clear_mode disables all modes set in |mode| (which should be one or more
825 // of the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
826 // representing the resulting enabled modes.
827 OPENSSL_EXPORT uint32_t SSL_clear_mode(SSL *ssl, uint32_t mode);
828 
829 // SSL_get_mode returns a bitmask of |SSL_MODE_*| values that represent all the
830 // modes enabled for |ssl|.
831 OPENSSL_EXPORT uint32_t SSL_get_mode(const SSL *ssl);
832 
833 // SSL_CTX_set0_buffer_pool sets a |CRYPTO_BUFFER_POOL| that will be used to
834 // store certificates. This can allow multiple connections to share
835 // certificates and thus save memory.
836 //
837 // The SSL_CTX does not take ownership of |pool| and the caller must ensure
838 // that |pool| outlives |ctx| and all objects linked to it, including |SSL|,
839 // |X509| and |SSL_SESSION| objects. Basically, don't ever free |pool|.
840 OPENSSL_EXPORT void SSL_CTX_set0_buffer_pool(SSL_CTX *ctx,
841                                              CRYPTO_BUFFER_POOL *pool);
842 
843 
844 // Credentials.
845 //
846 // TLS endpoints may present authentication during the handshake, usually using
847 // X.509 certificates. This is typically required for servers and optional for
848 // clients. BoringSSL uses the |SSL_CREDENTIAL| object to abstract between
849 // different kinds of credentials, as well as configure automatic selection
850 // between multiple credentials. This may be used to select between ECDSA and
851 // RSA certificates.
852 //
853 // |SSL_CTX| and |SSL| objects maintain lists of credentials in preference
854 // order. During the handshake, BoringSSL will select the first usable
855 // credential from the list. Non-credential APIs, such as
856 // |SSL_CTX_use_certificate|, configure a "default credential", which is
857 // appended to this list if configured.
858 //
859 // When selecting credentials, BoringSSL considers the credential's type, its
860 // cryptographic capabilities, and capabilities advertised by the peer. This
861 // varies between TLS versions but includes:
862 //
863 // - Whether the peer supports the leaf certificate key
864 // - Whether there is a common signature algorithm that is compatible with the
865 //   credential
866 // - Whether there is a common cipher suite that is compatible with the
867 //   credential
868 //
869 // WARNING: In TLS 1.2 and below, there is no mechanism for servers to advertise
870 // supported ECDSA curves to the client. BoringSSL clients will assume the
871 // server accepts all ECDSA curves in client certificates.
872 //
873 // By default, BoringSSL does not check the following, though we may add APIs
874 // in the future to enable them on a per-credential basis.
875 //
876 // - Whether the peer supports the signature algorithms in the certificate chain
877 // - Whether the a server certificate is compatible with the server_name
878 //   extension (SNI)
879 // - Whether the peer supports the certificate authority that issued the
880 //   certificate
881 //
882 // Credentials may be configured before the handshake or dynamically in the
883 // early callback (see |SSL_CTX_set_select_certificate_cb|) and certificate
884 // callback (see |SSL_CTX_set_cert_cb|). These callbacks allow applications to
885 // use BoringSSL's built-in selection logic in tandem with custom logic. For
886 // example, a callback could evaluate application-specific SNI rules to filter
887 // down to an ECDSA and RSA credential, then configure both for BoringSSL to
888 // select between the two.
889 
890 // SSL_CREDENTIAL_new_x509 returns a new, empty X.509 credential, or NULL on
891 // error. Callers should release the result with |SSL_CREDENTIAL_free| when
892 // done.
893 //
894 // Callers should configure a certificate chain and private key on the
895 // credential, along with other properties, then add it with
896 // |SSL_CTX_add1_credential|.
897 OPENSSL_EXPORT SSL_CREDENTIAL *SSL_CREDENTIAL_new_x509(void);
898 
899 // SSL_CREDENTIAL_up_ref increments the reference count of |cred|.
900 OPENSSL_EXPORT void SSL_CREDENTIAL_up_ref(SSL_CREDENTIAL *cred);
901 
902 // SSL_CREDENTIAL_free decrements the reference count of |cred|. If it reaches
903 // zero, all data referenced by |cred| and |cred| itself are released.
904 OPENSSL_EXPORT void SSL_CREDENTIAL_free(SSL_CREDENTIAL *cred);
905 
906 // SSL_CREDENTIAL_set1_private_key sets |cred|'s private key to |cred|. It
907 // returns one on success and zero on failure.
908 OPENSSL_EXPORT int SSL_CREDENTIAL_set1_private_key(SSL_CREDENTIAL *cred,
909                                                    EVP_PKEY *key);
910 
911 // SSL_CREDENTIAL_set1_signing_algorithm_prefs configures |cred| to use |prefs|
912 // as the preference list when signing with |cred|'s private key. It returns one
913 // on success and zero on error. |prefs| should not include the internal-only
914 // value |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
915 //
916 // It is an error to call this function with delegated credentials (see
917 // |SSL_CREDENTIAL_new_delegated|) because delegated credentials already
918 // constrain the key to a single algorithm.
919 OPENSSL_EXPORT int SSL_CREDENTIAL_set1_signing_algorithm_prefs(
920     SSL_CREDENTIAL *cred, const uint16_t *prefs, size_t num_prefs);
921 
922 // SSL_CREDENTIAL_set1_cert_chain sets |cred|'s certificate chain, starting from
923 // the leaf, to |num_cert|s certificates from |certs|. It returns one on success
924 // and zero on error.
925 OPENSSL_EXPORT int SSL_CREDENTIAL_set1_cert_chain(SSL_CREDENTIAL *cred,
926                                                   CRYPTO_BUFFER *const *certs,
927                                                   size_t num_certs);
928 
929 // SSL_CREDENTIAL_set1_ocsp_response sets |cred|'s stapled OCSP response to
930 // |ocsp|. It returns one on success and zero on error.
931 OPENSSL_EXPORT int SSL_CREDENTIAL_set1_ocsp_response(SSL_CREDENTIAL *cred,
932                                                      CRYPTO_BUFFER *ocsp);
933 
934 // SSL_CREDENTIAL_set1_signed_cert_timestamp_list sets |cred|'s list of signed
935 // certificate timestamps |sct_list|. |sct_list| must contain one or more SCT
936 // structures serialised as a SignedCertificateTimestampList (see
937 // https://tools.ietf.org/html/rfc6962#section-3.3) – i.e. each SCT is prefixed
938 // by a big-endian, uint16 length and the concatenation of one or more such
939 // prefixed SCTs are themselves also prefixed by a uint16 length. It returns one
940 // on success and zero on error.
941 OPENSSL_EXPORT int SSL_CREDENTIAL_set1_signed_cert_timestamp_list(
942     SSL_CREDENTIAL *cred, CRYPTO_BUFFER *sct_list);
943 
944 // SSL_CTX_add1_credential appends |cred| to |ctx|'s credential list. It returns
945 // one on success and zero on error. The credential list is maintained in order
946 // of decreasing preference, so earlier calls are preferred over later calls.
947 //
948 // After calling this function, it is an error to modify |cred|. Doing so may
949 // result in inconsistent handshake behavior or race conditions.
950 OPENSSL_EXPORT int SSL_CTX_add1_credential(SSL_CTX *ctx, SSL_CREDENTIAL *cred);
951 
952 // SSL_add1_credential appends |cred| to |ssl|'s credential list. It returns one
953 // on success and zero on error. The credential list is maintained in order of
954 // decreasing preference, so earlier calls are preferred over later calls.
955 //
956 // After calling this function, it is an error to modify |cred|. Doing so may
957 // result in inconsistent handshake behavior or race conditions.
958 OPENSSL_EXPORT int SSL_add1_credential(SSL *ssl, SSL_CREDENTIAL *cred);
959 
960 // SSL_certs_clear removes all credentials configured on |ssl|. It also removes
961 // the certificate chain and private key on the default credential.
962 OPENSSL_EXPORT void SSL_certs_clear(SSL *ssl);
963 
964 // SSL_get0_selected_credential returns the credential in use in the current
965 // handshake on |ssl|. If there is current handshake on |ssl| or if the
966 // handshake has not progressed to this point, it returns NULL.
967 //
968 // This function is intended for use with |SSL_CREDENTIAL_get_ex_data|. It may
969 // be called from handshake callbacks, such as those in
970 // |SSL_PRIVATE_KEY_METHOD|, to trigger credential-specific behavior.
971 //
972 // In applications that use the older APIs, such as |SSL_use_certificate|, this
973 // function may return an internal |SSL_CREDENTIAL| object. This internal object
974 // will have no ex_data installed. To avoid this, it is recommended that callers
975 // moving to |SSL_CREDENTIAL| use the new APIs consistently.
976 OPENSSL_EXPORT const SSL_CREDENTIAL *SSL_get0_selected_credential(
977     const SSL *ssl);
978 
979 
980 // Configuring certificates and private keys.
981 //
982 // These functions configure the connection's leaf certificate, private key, and
983 // certificate chain. The certificate chain is ordered leaf to root (as sent on
984 // the wire) but does not include the leaf. Both client and server certificates
985 // use these functions.
986 //
987 // Prefer to configure the certificate before the private key. If configured in
988 // the other order, inconsistent private keys will be silently dropped, rather
989 // than return an error. Additionally, overwriting a previously-configured
990 // certificate and key pair only works if the certificate is configured first.
991 //
992 // Each of these functions configures the default credential. To select between
993 // multiple certificates, see |SSL_CREDENTIAL_new_x509| and related APIs.
994 
995 // SSL_CTX_use_certificate sets |ctx|'s leaf certificate to |x509|. It returns
996 // one on success and zero on failure. If |ctx| has a private key which is
997 // inconsistent with |x509|, the private key is silently dropped.
998 OPENSSL_EXPORT int SSL_CTX_use_certificate(SSL_CTX *ctx, X509 *x509);
999 
1000 // SSL_use_certificate sets |ssl|'s leaf certificate to |x509|. It returns one
1001 // on success and zero on failure. If |ssl| has a private key which is
1002 // inconsistent with |x509|, the private key is silently dropped.
1003 OPENSSL_EXPORT int SSL_use_certificate(SSL *ssl, X509 *x509);
1004 
1005 // SSL_CTX_use_PrivateKey sets |ctx|'s private key to |pkey|. It returns one on
1006 // success and zero on failure. If |ctx| had a private key or
1007 // |SSL_PRIVATE_KEY_METHOD| previously configured, it is replaced.
1008 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey);
1009 
1010 // SSL_use_PrivateKey sets |ssl|'s private key to |pkey|. It returns one on
1011 // success and zero on failure. If |ssl| had a private key or
1012 // |SSL_PRIVATE_KEY_METHOD| previously configured, it is replaced.
1013 OPENSSL_EXPORT int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey);
1014 
1015 // SSL_CTX_set0_chain sets |ctx|'s certificate chain, excluding the leaf, to
1016 // |chain|. On success, it returns one and takes ownership of |chain|.
1017 // Otherwise, it returns zero.
1018 OPENSSL_EXPORT int SSL_CTX_set0_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
1019 
1020 // SSL_CTX_set1_chain sets |ctx|'s certificate chain, excluding the leaf, to
1021 // |chain|. It returns one on success and zero on failure. The caller retains
1022 // ownership of |chain| and may release it freely.
1023 OPENSSL_EXPORT int SSL_CTX_set1_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
1024 
1025 // SSL_set0_chain sets |ssl|'s certificate chain, excluding the leaf, to
1026 // |chain|. On success, it returns one and takes ownership of |chain|.
1027 // Otherwise, it returns zero.
1028 OPENSSL_EXPORT int SSL_set0_chain(SSL *ssl, STACK_OF(X509) *chain);
1029 
1030 // SSL_set1_chain sets |ssl|'s certificate chain, excluding the leaf, to
1031 // |chain|. It returns one on success and zero on failure. The caller retains
1032 // ownership of |chain| and may release it freely.
1033 OPENSSL_EXPORT int SSL_set1_chain(SSL *ssl, STACK_OF(X509) *chain);
1034 
1035 // SSL_CTX_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On
1036 // success, it returns one and takes ownership of |x509|. Otherwise, it returns
1037 // zero.
1038 OPENSSL_EXPORT int SSL_CTX_add0_chain_cert(SSL_CTX *ctx, X509 *x509);
1039 
1040 // SSL_CTX_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It
1041 // returns one on success and zero on failure. The caller retains ownership of
1042 // |x509| and may release it freely.
1043 OPENSSL_EXPORT int SSL_CTX_add1_chain_cert(SSL_CTX *ctx, X509 *x509);
1044 
1045 // SSL_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On success,
1046 // it returns one and takes ownership of |x509|. Otherwise, it returns zero.
1047 OPENSSL_EXPORT int SSL_add0_chain_cert(SSL *ssl, X509 *x509);
1048 
1049 // SSL_CTX_add_extra_chain_cert calls |SSL_CTX_add0_chain_cert|.
1050 OPENSSL_EXPORT int SSL_CTX_add_extra_chain_cert(SSL_CTX *ctx, X509 *x509);
1051 
1052 // SSL_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It returns
1053 // one on success and zero on failure. The caller retains ownership of |x509|
1054 // and may release it freely.
1055 OPENSSL_EXPORT int SSL_add1_chain_cert(SSL *ssl, X509 *x509);
1056 
1057 // SSL_CTX_clear_chain_certs clears |ctx|'s certificate chain and returns
1058 // one.
1059 OPENSSL_EXPORT int SSL_CTX_clear_chain_certs(SSL_CTX *ctx);
1060 
1061 // SSL_CTX_clear_extra_chain_certs calls |SSL_CTX_clear_chain_certs|.
1062 OPENSSL_EXPORT int SSL_CTX_clear_extra_chain_certs(SSL_CTX *ctx);
1063 
1064 // SSL_clear_chain_certs clears |ssl|'s certificate chain and returns one.
1065 OPENSSL_EXPORT int SSL_clear_chain_certs(SSL *ssl);
1066 
1067 // SSL_CTX_set_cert_cb sets a callback that is called to select a certificate.
1068 // The callback returns one on success, zero on internal error, and a negative
1069 // number on failure or to pause the handshake. If the handshake is paused,
1070 // |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
1071 //
1072 // On the client, the callback may call |SSL_get0_certificate_types| and
1073 // |SSL_get_client_CA_list| for information on the server's certificate
1074 // request.
1075 //
1076 // On the server, the callback will be called after extensions have been
1077 // processed, but before the resumption decision has been made. This differs
1078 // from OpenSSL which handles resumption before selecting the certificate.
1079 OPENSSL_EXPORT void SSL_CTX_set_cert_cb(SSL_CTX *ctx,
1080                                         int (*cb)(SSL *ssl, void *arg),
1081                                         void *arg);
1082 
1083 // SSL_set_cert_cb sets a callback that is called to select a certificate. The
1084 // callback returns one on success, zero on internal error, and a negative
1085 // number on failure or to pause the handshake. If the handshake is paused,
1086 // |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
1087 //
1088 // On the client, the callback may call |SSL_get0_certificate_types| and
1089 // |SSL_get_client_CA_list| for information on the server's certificate
1090 // request.
1091 //
1092 // On the server, the callback will be called after extensions have been
1093 // processed, but before the resumption decision has been made. This differs
1094 // from OpenSSL which handles resumption before selecting the certificate.
1095 OPENSSL_EXPORT void SSL_set_cert_cb(SSL *ssl, int (*cb)(SSL *ssl, void *arg),
1096                                     void *arg);
1097 
1098 // SSL_get0_certificate_types, for a client, sets |*out_types| to an array
1099 // containing the client certificate types requested by a server. It returns the
1100 // length of the array. Note this list is always empty in TLS 1.3. The server
1101 // will instead send signature algorithms. See
1102 // |SSL_get0_peer_verify_algorithms|.
1103 //
1104 // The behavior of this function is undefined except during the callbacks set by
1105 // by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
1106 // handshake is paused because of them.
1107 OPENSSL_EXPORT size_t SSL_get0_certificate_types(const SSL *ssl,
1108                                                  const uint8_t **out_types);
1109 
1110 // SSL_get0_peer_verify_algorithms sets |*out_sigalgs| to an array containing
1111 // the signature algorithms the peer is able to verify. It returns the length of
1112 // the array. Note these values are only sent starting TLS 1.2 and only
1113 // mandatory starting TLS 1.3. If not sent, the empty array is returned. For the
1114 // historical client certificate types list, see |SSL_get0_certificate_types|.
1115 //
1116 // The behavior of this function is undefined except during the callbacks set by
1117 // by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
1118 // handshake is paused because of them.
1119 OPENSSL_EXPORT size_t
1120 SSL_get0_peer_verify_algorithms(const SSL *ssl, const uint16_t **out_sigalgs);
1121 
1122 // SSL_get0_peer_delegation_algorithms sets |*out_sigalgs| to an array
1123 // containing the signature algorithms the peer is willing to use with delegated
1124 // credentials.  It returns the length of the array. If not sent, the empty
1125 // array is returned.
1126 //
1127 // The behavior of this function is undefined except during the callbacks set by
1128 // by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
1129 // handshake is paused because of them.
1130 OPENSSL_EXPORT size_t
1131 SSL_get0_peer_delegation_algorithms(const SSL *ssl,
1132                                     const uint16_t **out_sigalgs);
1133 
1134 // SSL_CTX_get0_certificate returns |ctx|'s leaf certificate.
1135 OPENSSL_EXPORT X509 *SSL_CTX_get0_certificate(const SSL_CTX *ctx);
1136 
1137 // SSL_get_certificate returns |ssl|'s leaf certificate.
1138 OPENSSL_EXPORT X509 *SSL_get_certificate(const SSL *ssl);
1139 
1140 // SSL_CTX_get0_privatekey returns |ctx|'s private key.
1141 OPENSSL_EXPORT EVP_PKEY *SSL_CTX_get0_privatekey(const SSL_CTX *ctx);
1142 
1143 // SSL_get_privatekey returns |ssl|'s private key.
1144 OPENSSL_EXPORT EVP_PKEY *SSL_get_privatekey(const SSL *ssl);
1145 
1146 // SSL_CTX_get0_chain_certs sets |*out_chain| to |ctx|'s certificate chain and
1147 // returns one.
1148 OPENSSL_EXPORT int SSL_CTX_get0_chain_certs(const SSL_CTX *ctx,
1149                                             STACK_OF(X509) **out_chain);
1150 
1151 // SSL_CTX_get_extra_chain_certs calls |SSL_CTX_get0_chain_certs|.
1152 OPENSSL_EXPORT int SSL_CTX_get_extra_chain_certs(const SSL_CTX *ctx,
1153                                                  STACK_OF(X509) **out_chain);
1154 
1155 // SSL_get0_chain_certs sets |*out_chain| to |ssl|'s certificate chain and
1156 // returns one.
1157 OPENSSL_EXPORT int SSL_get0_chain_certs(const SSL *ssl,
1158                                         STACK_OF(X509) **out_chain);
1159 
1160 // SSL_CTX_set_signed_cert_timestamp_list sets the list of signed certificate
1161 // timestamps that is sent to clients that request it. The |list| argument must
1162 // contain one or more SCT structures serialised as a SignedCertificateTimestamp
1163 // List (see https://tools.ietf.org/html/rfc6962#section-3.3) – i.e. each SCT
1164 // is prefixed by a big-endian, uint16 length and the concatenation of one or
1165 // more such prefixed SCTs are themselves also prefixed by a uint16 length. It
1166 // returns one on success and zero on error. The caller retains ownership of
1167 // |list|.
1168 OPENSSL_EXPORT int SSL_CTX_set_signed_cert_timestamp_list(SSL_CTX *ctx,
1169                                                           const uint8_t *list,
1170                                                           size_t list_len);
1171 
1172 // SSL_set_signed_cert_timestamp_list sets the list of signed certificate
1173 // timestamps that is sent to clients that request is. The same format as the
1174 // one used for |SSL_CTX_set_signed_cert_timestamp_list| applies. The caller
1175 // retains ownership of |list|.
1176 OPENSSL_EXPORT int SSL_set_signed_cert_timestamp_list(SSL *ctx,
1177                                                       const uint8_t *list,
1178                                                       size_t list_len);
1179 
1180 // SSL_CTX_set_ocsp_response sets the OCSP response that is sent to clients
1181 // which request it. It returns one on success and zero on error. The caller
1182 // retains ownership of |response|.
1183 OPENSSL_EXPORT int SSL_CTX_set_ocsp_response(SSL_CTX *ctx,
1184                                              const uint8_t *response,
1185                                              size_t response_len);
1186 
1187 // SSL_set_ocsp_response sets the OCSP response that is sent to clients which
1188 // request it. It returns one on success and zero on error. The caller retains
1189 // ownership of |response|.
1190 OPENSSL_EXPORT int SSL_set_ocsp_response(SSL *ssl,
1191                                          const uint8_t *response,
1192                                          size_t response_len);
1193 
1194 // SSL_SIGN_* are signature algorithm values as defined in TLS 1.3.
1195 #define SSL_SIGN_RSA_PKCS1_SHA1 0x0201
1196 #define SSL_SIGN_RSA_PKCS1_SHA256 0x0401
1197 #define SSL_SIGN_RSA_PKCS1_SHA384 0x0501
1198 #define SSL_SIGN_RSA_PKCS1_SHA512 0x0601
1199 #define SSL_SIGN_ECDSA_SHA1 0x0203
1200 #define SSL_SIGN_ECDSA_SECP256R1_SHA256 0x0403
1201 #define SSL_SIGN_ECDSA_SECP384R1_SHA384 0x0503
1202 #define SSL_SIGN_ECDSA_SECP521R1_SHA512 0x0603
1203 #define SSL_SIGN_RSA_PSS_RSAE_SHA256 0x0804
1204 #define SSL_SIGN_RSA_PSS_RSAE_SHA384 0x0805
1205 #define SSL_SIGN_RSA_PSS_RSAE_SHA512 0x0806
1206 #define SSL_SIGN_ED25519 0x0807
1207 
1208 // SSL_SIGN_RSA_PKCS1_MD5_SHA1 is an internal signature algorithm used to
1209 // specify raw RSASSA-PKCS1-v1_5 with an MD5/SHA-1 concatenation, as used in TLS
1210 // before TLS 1.2.
1211 #define SSL_SIGN_RSA_PKCS1_MD5_SHA1 0xff01
1212 
1213 // SSL_get_signature_algorithm_name returns a human-readable name for |sigalg|,
1214 // or NULL if unknown. If |include_curve| is one, the curve for ECDSA algorithms
1215 // is included as in TLS 1.3. Otherwise, it is excluded as in TLS 1.2.
1216 OPENSSL_EXPORT const char *SSL_get_signature_algorithm_name(uint16_t sigalg,
1217                                                             int include_curve);
1218 
1219 // SSL_get_all_signature_algorithm_names outputs a list of possible strings
1220 // |SSL_get_signature_algorithm_name| may return in this version of BoringSSL.
1221 // It writes at most |max_out| entries to |out| and returns the total number it
1222 // would have written, if |max_out| had been large enough. |max_out| may be
1223 // initially set to zero to size the output.
1224 //
1225 // This function is only intended to help initialize tables in callers that want
1226 // possible strings pre-declared. This list would not be suitable to set a list
1227 // of supported features. It is in no particular order, and may contain
1228 // placeholder, experimental, or deprecated values that do not apply to every
1229 // caller. Future versions of BoringSSL may also return strings not in this
1230 // list, so this does not apply if, say, sending strings across services.
1231 OPENSSL_EXPORT size_t SSL_get_all_signature_algorithm_names(const char **out,
1232                                                             size_t max_out);
1233 
1234 // SSL_get_signature_algorithm_key_type returns the key type associated with
1235 // |sigalg| as an |EVP_PKEY_*| constant or |EVP_PKEY_NONE| if unknown.
1236 OPENSSL_EXPORT int SSL_get_signature_algorithm_key_type(uint16_t sigalg);
1237 
1238 // SSL_get_signature_algorithm_digest returns the digest function associated
1239 // with |sigalg| or |NULL| if |sigalg| has no prehash (Ed25519) or is unknown.
1240 OPENSSL_EXPORT const EVP_MD *SSL_get_signature_algorithm_digest(
1241     uint16_t sigalg);
1242 
1243 // SSL_is_signature_algorithm_rsa_pss returns one if |sigalg| is an RSA-PSS
1244 // signature algorithm and zero otherwise.
1245 OPENSSL_EXPORT int SSL_is_signature_algorithm_rsa_pss(uint16_t sigalg);
1246 
1247 // SSL_CTX_set_signing_algorithm_prefs configures |ctx| to use |prefs| as the
1248 // preference list when signing with |ctx|'s private key. It returns one on
1249 // success and zero on error. |prefs| should not include the internal-only value
1250 // |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
1251 OPENSSL_EXPORT int SSL_CTX_set_signing_algorithm_prefs(SSL_CTX *ctx,
1252                                                        const uint16_t *prefs,
1253                                                        size_t num_prefs);
1254 
1255 // SSL_set_signing_algorithm_prefs configures |ssl| to use |prefs| as the
1256 // preference list when signing with |ssl|'s private key. It returns one on
1257 // success and zero on error. |prefs| should not include the internal-only value
1258 // |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
1259 OPENSSL_EXPORT int SSL_set_signing_algorithm_prefs(SSL *ssl,
1260                                                    const uint16_t *prefs,
1261                                                    size_t num_prefs);
1262 
1263 
1264 // Certificate and private key convenience functions.
1265 
1266 // SSL_CTX_set_chain_and_key sets the certificate chain and private key for a
1267 // TLS client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
1268 // objects are added as needed. Exactly one of |privkey| or |privkey_method|
1269 // may be non-NULL. Returns one on success and zero on error.
1270 OPENSSL_EXPORT int SSL_CTX_set_chain_and_key(
1271     SSL_CTX *ctx, CRYPTO_BUFFER *const *certs, size_t num_certs,
1272     EVP_PKEY *privkey, const SSL_PRIVATE_KEY_METHOD *privkey_method);
1273 
1274 // SSL_set_chain_and_key sets the certificate chain and private key for a TLS
1275 // client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
1276 // objects are added as needed. Exactly one of |privkey| or |privkey_method|
1277 // may be non-NULL. Returns one on success and zero on error.
1278 OPENSSL_EXPORT int SSL_set_chain_and_key(
1279     SSL *ssl, CRYPTO_BUFFER *const *certs, size_t num_certs, EVP_PKEY *privkey,
1280     const SSL_PRIVATE_KEY_METHOD *privkey_method);
1281 
1282 // SSL_CTX_get0_chain returns the list of |CRYPTO_BUFFER|s that were set by
1283 // |SSL_CTX_set_chain_and_key|. Reference counts are not incremented by this
1284 // call. The return value may be |NULL| if no chain has been set.
1285 //
1286 // (Note: if a chain was configured by non-|CRYPTO_BUFFER|-based functions then
1287 // the return value is undefined and, even if not NULL, the stack itself may
1288 // contain nullptrs. Thus you shouldn't mix this function with
1289 // non-|CRYPTO_BUFFER| functions for manipulating the chain.)
1290 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER) *SSL_CTX_get0_chain(
1291     const SSL_CTX *ctx);
1292 
1293 // SSL_get0_chain returns the list of |CRYPTO_BUFFER|s that were set by
1294 // |SSL_set_chain_and_key|, unless they have been discarded. Reference counts
1295 // are not incremented by this call. The return value may be |NULL| if no chain
1296 // has been set.
1297 //
1298 // (Note: if a chain was configured by non-|CRYPTO_BUFFER|-based functions then
1299 // the return value is undefined and, even if not NULL, the stack itself may
1300 // contain nullptrs. Thus you shouldn't mix this function with
1301 // non-|CRYPTO_BUFFER| functions for manipulating the chain.)
1302 //
1303 // This function may return nullptr if a handshake has completed even if
1304 // |SSL_set_chain_and_key| was previously called, since the configuration
1305 // containing the certificates is typically cleared after handshake completion.
1306 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER) *SSL_get0_chain(const SSL *ssl);
1307 
1308 // SSL_CTX_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one
1309 // on success and zero on failure.
1310 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa);
1311 
1312 // SSL_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one on
1313 // success and zero on failure.
1314 OPENSSL_EXPORT int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa);
1315 
1316 // The following functions configure certificates or private keys but take as
1317 // input DER-encoded structures. They return one on success and zero on
1318 // failure.
1319 
1320 OPENSSL_EXPORT int SSL_CTX_use_certificate_ASN1(SSL_CTX *ctx, size_t der_len,
1321                                                 const uint8_t *der);
1322 OPENSSL_EXPORT int SSL_use_certificate_ASN1(SSL *ssl, const uint8_t *der,
1323                                             size_t der_len);
1324 
1325 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_ASN1(int pk, SSL_CTX *ctx,
1326                                                const uint8_t *der,
1327                                                size_t der_len);
1328 OPENSSL_EXPORT int SSL_use_PrivateKey_ASN1(int type, SSL *ssl,
1329                                            const uint8_t *der, size_t der_len);
1330 
1331 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx,
1332                                                   const uint8_t *der,
1333                                                   size_t der_len);
1334 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der,
1335                                               size_t der_len);
1336 
1337 // The following functions configure certificates or private keys but take as
1338 // input files to read from. They return one on success and zero on failure. The
1339 // |type| parameter is one of the |SSL_FILETYPE_*| values and determines whether
1340 // the file's contents are read as PEM or DER.
1341 
1342 #define SSL_FILETYPE_PEM 1
1343 #define SSL_FILETYPE_ASN1 2
1344 
1345 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_file(SSL_CTX *ctx,
1346                                                   const char *file,
1347                                                   int type);
1348 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_file(SSL *ssl, const char *file,
1349                                               int type);
1350 
1351 OPENSSL_EXPORT int SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file,
1352                                                 int type);
1353 OPENSSL_EXPORT int SSL_use_certificate_file(SSL *ssl, const char *file,
1354                                             int type);
1355 
1356 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx, const char *file,
1357                                                int type);
1358 OPENSSL_EXPORT int SSL_use_PrivateKey_file(SSL *ssl, const char *file,
1359                                            int type);
1360 
1361 // SSL_CTX_use_certificate_chain_file configures certificates for |ctx|. It
1362 // reads the contents of |file| as a PEM-encoded leaf certificate followed
1363 // optionally by the certificate chain to send to the peer. It returns one on
1364 // success and zero on failure.
1365 //
1366 // WARNING: If the input contains "TRUSTED CERTIFICATE" PEM blocks, this
1367 // function parses auxiliary properties as in |d2i_X509_AUX|. Passing untrusted
1368 // input to this function allows an attacker to influence those properties. See
1369 // |d2i_X509_AUX| for details.
1370 OPENSSL_EXPORT int SSL_CTX_use_certificate_chain_file(SSL_CTX *ctx,
1371                                                       const char *file);
1372 
1373 // SSL_CTX_set_default_passwd_cb sets the password callback for PEM-based
1374 // convenience functions called on |ctx|.
1375 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb(SSL_CTX *ctx,
1376                                                   pem_password_cb *cb);
1377 
1378 // SSL_CTX_get_default_passwd_cb returns the callback set by
1379 // |SSL_CTX_set_default_passwd_cb|.
1380 OPENSSL_EXPORT pem_password_cb *SSL_CTX_get_default_passwd_cb(
1381     const SSL_CTX *ctx);
1382 
1383 // SSL_CTX_set_default_passwd_cb_userdata sets the userdata parameter for
1384 // |ctx|'s password callback.
1385 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb_userdata(SSL_CTX *ctx,
1386                                                            void *data);
1387 
1388 // SSL_CTX_get_default_passwd_cb_userdata returns the userdata parameter set by
1389 // |SSL_CTX_set_default_passwd_cb_userdata|.
1390 OPENSSL_EXPORT void *SSL_CTX_get_default_passwd_cb_userdata(const SSL_CTX *ctx);
1391 
1392 
1393 // Custom private keys.
1394 
1395 enum ssl_private_key_result_t BORINGSSL_ENUM_INT {
1396   ssl_private_key_success,
1397   ssl_private_key_retry,
1398   ssl_private_key_failure,
1399 };
1400 
1401 // ssl_private_key_method_st (aka |SSL_PRIVATE_KEY_METHOD|) describes private
1402 // key hooks. This is used to off-load signing operations to a custom,
1403 // potentially asynchronous, backend. Metadata about the key such as the type
1404 // and size are parsed out of the certificate.
1405 struct ssl_private_key_method_st {
1406   // sign signs the message |in| in using the specified signature algorithm. On
1407   // success, it returns |ssl_private_key_success| and writes at most |max_out|
1408   // bytes of signature data to |out| and sets |*out_len| to the number of bytes
1409   // written. On failure, it returns |ssl_private_key_failure|. If the operation
1410   // has not completed, it returns |ssl_private_key_retry|. |sign| should
1411   // arrange for the high-level operation on |ssl| to be retried when the
1412   // operation is completed. This will result in a call to |complete|.
1413   //
1414   // |signature_algorithm| is one of the |SSL_SIGN_*| values, as defined in TLS
1415   // 1.3. Note that, in TLS 1.2, ECDSA algorithms do not require that curve
1416   // sizes match hash sizes, so the curve portion of |SSL_SIGN_ECDSA_*| values
1417   // must be ignored. BoringSSL will internally handle the curve matching logic
1418   // where appropriate.
1419   //
1420   // It is an error to call |sign| while another private key operation is in
1421   // progress on |ssl|.
1422   enum ssl_private_key_result_t (*sign)(SSL *ssl, uint8_t *out, size_t *out_len,
1423                                         size_t max_out,
1424                                         uint16_t signature_algorithm,
1425                                         const uint8_t *in, size_t in_len);
1426 
1427   // decrypt decrypts |in_len| bytes of encrypted data from |in|. On success it
1428   // returns |ssl_private_key_success|, writes at most |max_out| bytes of
1429   // decrypted data to |out| and sets |*out_len| to the actual number of bytes
1430   // written. On failure it returns |ssl_private_key_failure|. If the operation
1431   // has not completed, it returns |ssl_private_key_retry|. The caller should
1432   // arrange for the high-level operation on |ssl| to be retried when the
1433   // operation is completed, which will result in a call to |complete|. This
1434   // function only works with RSA keys and should perform a raw RSA decryption
1435   // operation with no padding.
1436   //
1437   // It is an error to call |decrypt| while another private key operation is in
1438   // progress on |ssl|.
1439   enum ssl_private_key_result_t (*decrypt)(SSL *ssl, uint8_t *out,
1440                                            size_t *out_len, size_t max_out,
1441                                            const uint8_t *in, size_t in_len);
1442 
1443   // complete completes a pending operation. If the operation has completed, it
1444   // returns |ssl_private_key_success| and writes the result to |out| as in
1445   // |sign|. Otherwise, it returns |ssl_private_key_failure| on failure and
1446   // |ssl_private_key_retry| if the operation is still in progress.
1447   //
1448   // |complete| may be called arbitrarily many times before completion, but it
1449   // is an error to call |complete| if there is no pending operation in progress
1450   // on |ssl|.
1451   enum ssl_private_key_result_t (*complete)(SSL *ssl, uint8_t *out,
1452                                             size_t *out_len, size_t max_out);
1453 };
1454 
1455 // SSL_set_private_key_method configures a custom private key on |ssl|.
1456 // |key_method| must remain valid for the lifetime of |ssl|.
1457 //
1458 // If using an RSA or ECDSA key, callers should configure signing capabilities
1459 // with |SSL_set_signing_algorithm_prefs|. Otherwise, BoringSSL may select a
1460 // signature algorithm that |key_method| does not support.
1461 OPENSSL_EXPORT void SSL_set_private_key_method(
1462     SSL *ssl, const SSL_PRIVATE_KEY_METHOD *key_method);
1463 
1464 // SSL_CTX_set_private_key_method configures a custom private key on |ctx|.
1465 // |key_method| must remain valid for the lifetime of |ctx|.
1466 //
1467 // If using an RSA or ECDSA key, callers should configure signing capabilities
1468 // with |SSL_CTX_set_signing_algorithm_prefs|. Otherwise, BoringSSL may select a
1469 // signature algorithm that |key_method| does not support.
1470 OPENSSL_EXPORT void SSL_CTX_set_private_key_method(
1471     SSL_CTX *ctx, const SSL_PRIVATE_KEY_METHOD *key_method);
1472 
1473 // SSL_CREDENTIAL_set_private_key_method configures a custom private key on
1474 // |cred|. |key_method| must remain valid for the lifetime of |cred|. It returns
1475 // one on success and zero if |cred| does not use private keys.
1476 //
1477 // If using an RSA or ECDSA key, callers should configure signing capabilities
1478 // with |SSL_CREDENTIAL_set1_signing_algorithm_prefs|. Otherwise, BoringSSL may
1479 // select a signature algorithm that |key_method| does not support. This is not
1480 // necessary for delegated credentials (see |SSL_CREDENTIAL_new_delegated|)
1481 // because delegated credentials only support a single signature algorithm.
1482 //
1483 // Functions in |key_method| will be passed an |SSL| object, but not |cred|
1484 // directly. Use |SSL_get0_selected_credential| to determine the selected
1485 // credential. From there, |SSL_CREDENTIAL_get_ex_data| can be used to look up
1486 // credential-specific state, such as a handle to the private key.
1487 OPENSSL_EXPORT int SSL_CREDENTIAL_set_private_key_method(
1488     SSL_CREDENTIAL *cred, const SSL_PRIVATE_KEY_METHOD *key_method);
1489 
1490 // SSL_can_release_private_key returns one if |ssl| will no longer call into the
1491 // private key and zero otherwise. If the function returns one, the caller can
1492 // release state associated with the private key.
1493 //
1494 // NOTE: This function assumes the caller does not use |SSL_clear| to reuse
1495 // |ssl| for a second connection. If |SSL_clear| is used, BoringSSL may still
1496 // use the private key on the second connection.
1497 OPENSSL_EXPORT int SSL_can_release_private_key(const SSL *ssl);
1498 
1499 
1500 // Cipher suites.
1501 //
1502 // |SSL_CIPHER| objects represent cipher suites.
1503 
1504 DEFINE_CONST_STACK_OF(SSL_CIPHER)
1505 
1506 // SSL_get_cipher_by_value returns the structure representing a TLS cipher
1507 // suite based on its assigned number, or NULL if unknown. See
1508 // https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4.
1509 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value);
1510 
1511 // SSL_CIPHER_get_id returns |cipher|'s non-IANA id. This is not its
1512 // IANA-assigned number, which is called the "value" here, although it may be
1513 // cast to a |uint16_t| to get it.
1514 OPENSSL_EXPORT uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher);
1515 
1516 // SSL_CIPHER_get_protocol_id returns |cipher|'s IANA-assigned number.
1517 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_protocol_id(const SSL_CIPHER *cipher);
1518 
1519 // SSL_CIPHER_is_aead returns one if |cipher| uses an AEAD cipher.
1520 OPENSSL_EXPORT int SSL_CIPHER_is_aead(const SSL_CIPHER *cipher);
1521 
1522 // SSL_CIPHER_is_block_cipher returns one if |cipher| is a block cipher.
1523 OPENSSL_EXPORT int SSL_CIPHER_is_block_cipher(const SSL_CIPHER *cipher);
1524 
1525 // SSL_CIPHER_get_cipher_nid returns the NID for |cipher|'s bulk
1526 // cipher. Possible values are |NID_aes_128_gcm|, |NID_aes_256_gcm|,
1527 // |NID_chacha20_poly1305|, |NID_aes_128_cbc|, |NID_aes_256_cbc|, and
1528 // |NID_des_ede3_cbc|.
1529 OPENSSL_EXPORT int SSL_CIPHER_get_cipher_nid(const SSL_CIPHER *cipher);
1530 
1531 // SSL_CIPHER_get_digest_nid returns the NID for |cipher|'s HMAC if it is a
1532 // legacy cipher suite. For modern AEAD-based ciphers (see
1533 // |SSL_CIPHER_is_aead|), it returns |NID_undef|.
1534 //
1535 // Note this function only returns the legacy HMAC digest, not the PRF hash.
1536 OPENSSL_EXPORT int SSL_CIPHER_get_digest_nid(const SSL_CIPHER *cipher);
1537 
1538 // SSL_CIPHER_get_kx_nid returns the NID for |cipher|'s key exchange. This may
1539 // be |NID_kx_rsa|, |NID_kx_ecdhe|, or |NID_kx_psk| for TLS 1.2. In TLS 1.3,
1540 // cipher suites do not specify the key exchange, so this function returns
1541 // |NID_kx_any|.
1542 OPENSSL_EXPORT int SSL_CIPHER_get_kx_nid(const SSL_CIPHER *cipher);
1543 
1544 // SSL_CIPHER_get_auth_nid returns the NID for |cipher|'s authentication
1545 // type. This may be |NID_auth_rsa|, |NID_auth_ecdsa|, or |NID_auth_psk| for TLS
1546 // 1.2. In TLS 1.3, cipher suites do not specify authentication, so this
1547 // function returns |NID_auth_any|.
1548 OPENSSL_EXPORT int SSL_CIPHER_get_auth_nid(const SSL_CIPHER *cipher);
1549 
1550 // SSL_CIPHER_get_handshake_digest returns |cipher|'s PRF hash. If |cipher|
1551 // is a pre-TLS-1.2 cipher, it returns |EVP_md5_sha1| but note these ciphers use
1552 // SHA-256 in TLS 1.2. Other return values may be treated uniformly in all
1553 // applicable versions.
1554 OPENSSL_EXPORT const EVP_MD *SSL_CIPHER_get_handshake_digest(
1555     const SSL_CIPHER *cipher);
1556 
1557 // SSL_CIPHER_get_prf_nid behaves like |SSL_CIPHER_get_handshake_digest| but
1558 // returns the NID constant. Use |SSL_CIPHER_get_handshake_digest| instead.
1559 OPENSSL_EXPORT int SSL_CIPHER_get_prf_nid(const SSL_CIPHER *cipher);
1560 
1561 // SSL_CIPHER_get_min_version returns the minimum protocol version required
1562 // for |cipher|.
1563 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_min_version(const SSL_CIPHER *cipher);
1564 
1565 // SSL_CIPHER_get_max_version returns the maximum protocol version that
1566 // supports |cipher|.
1567 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_max_version(const SSL_CIPHER *cipher);
1568 
1569 // SSL_CIPHER_standard_name returns the standard IETF name for |cipher|. For
1570 // example, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256".
1571 OPENSSL_EXPORT const char *SSL_CIPHER_standard_name(const SSL_CIPHER *cipher);
1572 
1573 // SSL_CIPHER_get_name returns the OpenSSL name of |cipher|. For example,
1574 // "ECDHE-RSA-AES128-GCM-SHA256". Callers are recommended to use
1575 // |SSL_CIPHER_standard_name| instead.
1576 OPENSSL_EXPORT const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher);
1577 
1578 // SSL_CIPHER_get_kx_name returns a string that describes the key-exchange
1579 // method used by |cipher|. For example, "ECDHE_ECDSA". TLS 1.3 AEAD-only
1580 // ciphers return the string "GENERIC".
1581 OPENSSL_EXPORT const char *SSL_CIPHER_get_kx_name(const SSL_CIPHER *cipher);
1582 
1583 // SSL_CIPHER_get_bits returns the strength, in bits, of |cipher|. If
1584 // |out_alg_bits| is not NULL, it writes the number of bits consumed by the
1585 // symmetric algorithm to |*out_alg_bits|.
1586 OPENSSL_EXPORT int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher,
1587                                        int *out_alg_bits);
1588 
1589 // SSL_get_all_cipher_names outputs a list of possible strings
1590 // |SSL_CIPHER_get_name| may return in this version of BoringSSL. It writes at
1591 // most |max_out| entries to |out| and returns the total number it would have
1592 // written, if |max_out| had been large enough. |max_out| may be initially set
1593 // to zero to size the output.
1594 //
1595 // This function is only intended to help initialize tables in callers that want
1596 // possible strings pre-declared. This list would not be suitable to set a list
1597 // of supported features. It is in no particular order, and may contain
1598 // placeholder, experimental, or deprecated values that do not apply to every
1599 // caller. Future versions of BoringSSL may also return strings not in this
1600 // list, so this does not apply if, say, sending strings across services.
1601 OPENSSL_EXPORT size_t SSL_get_all_cipher_names(const char **out,
1602                                                size_t max_out);
1603 
1604 
1605 // SSL_get_all_standard_cipher_names outputs a list of possible strings
1606 // |SSL_CIPHER_standard_name| may return in this version of BoringSSL. It writes
1607 // at most |max_out| entries to |out| and returns the total number it would have
1608 // written, if |max_out| had been large enough. |max_out| may be initially set
1609 // to zero to size the output.
1610 //
1611 // This function is only intended to help initialize tables in callers that want
1612 // possible strings pre-declared. This list would not be suitable to set a list
1613 // of supported features. It is in no particular order, and may contain
1614 // placeholder, experimental, or deprecated values that do not apply to every
1615 // caller. Future versions of BoringSSL may also return strings not in this
1616 // list, so this does not apply if, say, sending strings across services.
1617 OPENSSL_EXPORT size_t SSL_get_all_standard_cipher_names(const char **out,
1618                                                         size_t max_out);
1619 
1620 
1621 // Cipher suite configuration.
1622 //
1623 // OpenSSL uses a mini-language to configure cipher suites. The language
1624 // maintains an ordered list of enabled ciphers, along with an ordered list of
1625 // disabled but available ciphers. Initially, all ciphers are disabled with a
1626 // default ordering. The cipher string is then interpreted as a sequence of
1627 // directives, separated by colons, each of which modifies this state.
1628 //
1629 // Most directives consist of a one character or empty opcode followed by a
1630 // selector which matches a subset of available ciphers.
1631 //
1632 // Available opcodes are:
1633 //
1634 // - The empty opcode enables and appends all matching disabled ciphers to the
1635 //   end of the enabled list. The newly appended ciphers are ordered relative to
1636 //   each other matching their order in the disabled list.
1637 //
1638 // - |-| disables all matching enabled ciphers and prepends them to the disabled
1639 //   list, with relative order from the enabled list preserved. This means the
1640 //   most recently disabled ciphers get highest preference relative to other
1641 //   disabled ciphers if re-enabled.
1642 //
1643 // - |+| moves all matching enabled ciphers to the end of the enabled list, with
1644 //   relative order preserved.
1645 //
1646 // - |!| deletes all matching ciphers, enabled or not, from either list. Deleted
1647 //   ciphers will not matched by future operations.
1648 //
1649 // A selector may be a specific cipher (using either the standard or OpenSSL
1650 // name for the cipher) or one or more rules separated by |+|. The final
1651 // selector matches the intersection of each rule. For instance, |AESGCM+aECDSA|
1652 // matches ECDSA-authenticated AES-GCM ciphers.
1653 //
1654 // Available cipher rules are:
1655 //
1656 // - |ALL| matches all ciphers, except for deprecated ciphers which must be
1657 //   named explicitly.
1658 //
1659 // - |kRSA|, |kDHE|, |kECDHE|, and |kPSK| match ciphers using plain RSA, DHE,
1660 //   ECDHE, and plain PSK key exchanges, respectively. Note that ECDHE_PSK is
1661 //   matched by |kECDHE| and not |kPSK|.
1662 //
1663 // - |aRSA|, |aECDSA|, and |aPSK| match ciphers authenticated by RSA, ECDSA, and
1664 //   a pre-shared key, respectively.
1665 //
1666 // - |RSA|, |DHE|, |ECDHE|, |PSK|, |ECDSA|, and |PSK| are aliases for the
1667 //   corresponding |k*| or |a*| cipher rule. |RSA| is an alias for |kRSA|, not
1668 //   |aRSA|.
1669 //
1670 // - |3DES|, |AES128|, |AES256|, |AES|, |AESGCM|, |CHACHA20| match ciphers
1671 //   whose bulk cipher use the corresponding encryption scheme. Note that
1672 //   |AES|, |AES128|, and |AES256| match both CBC and GCM ciphers.
1673 //
1674 // - |SHA1|, and its alias |SHA|, match legacy cipher suites using HMAC-SHA1.
1675 //
1676 // Deprecated cipher rules:
1677 //
1678 // - |kEDH|, |EDH|, |kEECDH|, and |EECDH| are legacy aliases for |kDHE|, |DHE|,
1679 //   |kECDHE|, and |ECDHE|, respectively.
1680 //
1681 // - |HIGH| is an alias for |ALL|.
1682 //
1683 // - |FIPS| is an alias for |HIGH|.
1684 //
1685 // - |SSLv3| and |TLSv1| match ciphers available in TLS 1.1 or earlier.
1686 //   |TLSv1_2| matches ciphers new in TLS 1.2. This is confusing and should not
1687 //   be used.
1688 //
1689 // Unknown rules are silently ignored by legacy APIs, and rejected by APIs with
1690 // "strict" in the name, which should be preferred. Cipher lists can be long
1691 // and it's easy to commit typos. Strict functions will also reject the use of
1692 // spaces, semi-colons and commas as alternative separators.
1693 //
1694 // The special |@STRENGTH| directive will sort all enabled ciphers by strength.
1695 //
1696 // The |DEFAULT| directive, when appearing at the front of the string, expands
1697 // to the default ordering of available ciphers.
1698 //
1699 // If configuring a server, one may also configure equal-preference groups to
1700 // partially respect the client's preferences when
1701 // |SSL_OP_CIPHER_SERVER_PREFERENCE| is enabled. Ciphers in an equal-preference
1702 // group have equal priority and use the client order. This may be used to
1703 // enforce that AEADs are preferred but select AES-GCM vs. ChaCha20-Poly1305
1704 // based on client preferences. An equal-preference is specified with square
1705 // brackets, combining multiple selectors separated by |. For example:
1706 //
1707 //   [TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256|TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256]
1708 //
1709 // Once an equal-preference group is used, future directives must be
1710 // opcode-less. Inside an equal-preference group, spaces are not allowed.
1711 //
1712 // TLS 1.3 ciphers do not participate in this mechanism and instead have a
1713 // built-in preference order. Functions to set cipher lists do not affect TLS
1714 // 1.3, and functions to query the cipher list do not include TLS 1.3 ciphers.
1715 
1716 // SSL_DEFAULT_CIPHER_LIST is the default cipher suite configuration. It is
1717 // substituted when a cipher string starts with 'DEFAULT'.
1718 #define SSL_DEFAULT_CIPHER_LIST "ALL"
1719 
1720 // SSL_CTX_set_strict_cipher_list configures the cipher list for |ctx|,
1721 // evaluating |str| as a cipher string and returning error if |str| contains
1722 // anything meaningless. It returns one on success and zero on failure.
1723 OPENSSL_EXPORT int SSL_CTX_set_strict_cipher_list(SSL_CTX *ctx,
1724                                                   const char *str);
1725 
1726 // SSL_CTX_set_cipher_list configures the cipher list for |ctx|, evaluating
1727 // |str| as a cipher string. It returns one on success and zero on failure.
1728 //
1729 // Prefer to use |SSL_CTX_set_strict_cipher_list|. This function tolerates
1730 // garbage inputs, unless an empty cipher list results.
1731 OPENSSL_EXPORT int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str);
1732 
1733 // SSL_set_strict_cipher_list configures the cipher list for |ssl|, evaluating
1734 // |str| as a cipher string and returning error if |str| contains anything
1735 // meaningless. It returns one on success and zero on failure.
1736 OPENSSL_EXPORT int SSL_set_strict_cipher_list(SSL *ssl, const char *str);
1737 
1738 // SSL_set_cipher_list configures the cipher list for |ssl|, evaluating |str| as
1739 // a cipher string. It returns one on success and zero on failure.
1740 //
1741 // Prefer to use |SSL_set_strict_cipher_list|. This function tolerates garbage
1742 // inputs, unless an empty cipher list results.
1743 OPENSSL_EXPORT int SSL_set_cipher_list(SSL *ssl, const char *str);
1744 
1745 // SSL_CTX_get_ciphers returns the cipher list for |ctx|, in order of
1746 // preference.
1747 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_CTX_get_ciphers(const SSL_CTX *ctx);
1748 
1749 // SSL_CTX_cipher_in_group returns one if the |i|th cipher (see
1750 // |SSL_CTX_get_ciphers|) is in the same equipreference group as the one
1751 // following it and zero otherwise.
1752 OPENSSL_EXPORT int SSL_CTX_cipher_in_group(const SSL_CTX *ctx, size_t i);
1753 
1754 // SSL_get_ciphers returns the cipher list for |ssl|, in order of preference.
1755 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *ssl);
1756 
1757 
1758 // Connection information.
1759 
1760 // SSL_is_init_finished returns one if |ssl| has completed its initial handshake
1761 // and has no pending handshake. It returns zero otherwise.
1762 OPENSSL_EXPORT int SSL_is_init_finished(const SSL *ssl);
1763 
1764 // SSL_in_init returns one if |ssl| has a pending handshake and zero
1765 // otherwise.
1766 OPENSSL_EXPORT int SSL_in_init(const SSL *ssl);
1767 
1768 // SSL_in_false_start returns one if |ssl| has a pending handshake that is in
1769 // False Start. |SSL_write| may be called at this point without waiting for the
1770 // peer, but |SSL_read| will complete the handshake before accepting application
1771 // data.
1772 //
1773 // See also |SSL_MODE_ENABLE_FALSE_START|.
1774 OPENSSL_EXPORT int SSL_in_false_start(const SSL *ssl);
1775 
1776 // SSL_get_peer_certificate returns the peer's leaf certificate or NULL if the
1777 // peer did not use certificates. The caller must call |X509_free| on the
1778 // result to release it.
1779 OPENSSL_EXPORT X509 *SSL_get_peer_certificate(const SSL *ssl);
1780 
1781 // SSL_get_peer_cert_chain returns the peer's certificate chain or NULL if
1782 // unavailable or the peer did not use certificates. This is the unverified list
1783 // of certificates as sent by the peer, not the final chain built during
1784 // verification. The caller does not take ownership of the result.
1785 //
1786 // WARNING: This function behaves differently between client and server. If
1787 // |ssl| is a server, the returned chain does not include the leaf certificate.
1788 // If a client, it does.
1789 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_cert_chain(const SSL *ssl);
1790 
1791 // SSL_get_peer_full_cert_chain returns the peer's certificate chain, or NULL if
1792 // unavailable or the peer did not use certificates. This is the unverified list
1793 // of certificates as sent by the peer, not the final chain built during
1794 // verification. The caller does not take ownership of the result.
1795 //
1796 // This is the same as |SSL_get_peer_cert_chain| except that this function
1797 // always returns the full chain, i.e. the first element of the return value
1798 // (if any) will be the leaf certificate. In constrast,
1799 // |SSL_get_peer_cert_chain| returns only the intermediate certificates if the
1800 // |ssl| is a server.
1801 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_full_cert_chain(const SSL *ssl);
1802 
1803 // SSL_get0_peer_certificates returns the peer's certificate chain, or NULL if
1804 // unavailable or the peer did not use certificates. This is the unverified list
1805 // of certificates as sent by the peer, not the final chain built during
1806 // verification. The caller does not take ownership of the result.
1807 //
1808 // This is the |CRYPTO_BUFFER| variant of |SSL_get_peer_full_cert_chain|.
1809 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER) *
1810     SSL_get0_peer_certificates(const SSL *ssl);
1811 
1812 // SSL_get0_signed_cert_timestamp_list sets |*out| and |*out_len| to point to
1813 // |*out_len| bytes of SCT information from the server. This is only valid if
1814 // |ssl| is a client. The SCT information is a SignedCertificateTimestampList
1815 // (including the two leading length bytes).
1816 // See https://tools.ietf.org/html/rfc6962#section-3.3
1817 // If no SCT was received then |*out_len| will be zero on return.
1818 //
1819 // WARNING: the returned data is not guaranteed to be well formed.
1820 OPENSSL_EXPORT void SSL_get0_signed_cert_timestamp_list(const SSL *ssl,
1821                                                         const uint8_t **out,
1822                                                         size_t *out_len);
1823 
1824 // SSL_get0_ocsp_response sets |*out| and |*out_len| to point to |*out_len|
1825 // bytes of an OCSP response from the server. This is the DER encoding of an
1826 // OCSPResponse type as defined in RFC 2560.
1827 //
1828 // WARNING: the returned data is not guaranteed to be well formed.
1829 OPENSSL_EXPORT void SSL_get0_ocsp_response(const SSL *ssl, const uint8_t **out,
1830                                            size_t *out_len);
1831 
1832 // SSL_get_tls_unique writes at most |max_out| bytes of the tls-unique value
1833 // for |ssl| to |out| and sets |*out_len| to the number of bytes written. It
1834 // returns one on success or zero on error. In general |max_out| should be at
1835 // least 12.
1836 //
1837 // This function will always fail if the initial handshake has not completed.
1838 // The tls-unique value will change after a renegotiation but, since
1839 // renegotiations can be initiated by the server at any point, the higher-level
1840 // protocol must either leave them disabled or define states in which the
1841 // tls-unique value can be read.
1842 //
1843 // The tls-unique value is defined by
1844 // https://tools.ietf.org/html/rfc5929#section-3.1. Due to a weakness in the
1845 // TLS protocol, tls-unique is broken for resumed connections unless the
1846 // Extended Master Secret extension is negotiated. Thus this function will
1847 // return zero if |ssl| performed session resumption unless EMS was used when
1848 // negotiating the original session.
1849 OPENSSL_EXPORT int SSL_get_tls_unique(const SSL *ssl, uint8_t *out,
1850                                       size_t *out_len, size_t max_out);
1851 
1852 // SSL_get_extms_support returns one if the Extended Master Secret extension or
1853 // TLS 1.3 was negotiated. Otherwise, it returns zero.
1854 OPENSSL_EXPORT int SSL_get_extms_support(const SSL *ssl);
1855 
1856 // SSL_get_current_cipher returns cipher suite used by |ssl|, or NULL if it has
1857 // not been negotiated yet.
1858 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_current_cipher(const SSL *ssl);
1859 
1860 // SSL_session_reused returns one if |ssl| performed an abbreviated handshake
1861 // and zero otherwise.
1862 //
1863 // TODO(davidben): Hammer down the semantics of this API while a handshake,
1864 // initial or renego, is in progress.
1865 OPENSSL_EXPORT int SSL_session_reused(const SSL *ssl);
1866 
1867 // SSL_get_secure_renegotiation_support returns one if the peer supports secure
1868 // renegotiation (RFC 5746) or TLS 1.3. Otherwise, it returns zero.
1869 OPENSSL_EXPORT int SSL_get_secure_renegotiation_support(const SSL *ssl);
1870 
1871 // SSL_export_keying_material exports a value derived from the master secret, as
1872 // specified in RFC 5705. It writes |out_len| bytes to |out| given a label and
1873 // optional context. (Since a zero length context is allowed, the |use_context|
1874 // flag controls whether a context is included.)
1875 //
1876 // It returns one on success and zero otherwise.
1877 OPENSSL_EXPORT int SSL_export_keying_material(
1878     SSL *ssl, uint8_t *out, size_t out_len, const char *label, size_t label_len,
1879     const uint8_t *context, size_t context_len, int use_context);
1880 
1881 
1882 // Sessions.
1883 //
1884 // An |SSL_SESSION| represents an SSL session that may be resumed in an
1885 // abbreviated handshake. It is reference-counted and immutable. Once
1886 // established, an |SSL_SESSION| may be shared by multiple |SSL| objects on
1887 // different threads and must not be modified.
1888 //
1889 // Note the TLS notion of "session" is not suitable for application-level
1890 // session state. It is an optional caching mechanism for the handshake. Not all
1891 // connections within an application-level session will reuse TLS sessions. TLS
1892 // sessions may be dropped by the client or ignored by the server at any time.
1893 
1894 DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
1895 
1896 // SSL_SESSION_new returns a newly-allocated blank |SSL_SESSION| or NULL on
1897 // error. This may be useful when writing tests but should otherwise not be
1898 // used.
1899 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_new(const SSL_CTX *ctx);
1900 
1901 // SSL_SESSION_up_ref increments the reference count of |session| and returns
1902 // one.
1903 OPENSSL_EXPORT int SSL_SESSION_up_ref(SSL_SESSION *session);
1904 
1905 // SSL_SESSION_free decrements the reference count of |session|. If it reaches
1906 // zero, all data referenced by |session| and |session| itself are released.
1907 OPENSSL_EXPORT void SSL_SESSION_free(SSL_SESSION *session);
1908 
1909 // SSL_SESSION_to_bytes serializes |in| into a newly allocated buffer and sets
1910 // |*out_data| to that buffer and |*out_len| to its length. The caller takes
1911 // ownership of the buffer and must call |OPENSSL_free| when done. It returns
1912 // one on success and zero on error.
1913 OPENSSL_EXPORT int SSL_SESSION_to_bytes(const SSL_SESSION *in,
1914                                         uint8_t **out_data, size_t *out_len);
1915 
1916 // SSL_SESSION_to_bytes_for_ticket serializes |in|, but excludes the session
1917 // identification information, namely the session ID and ticket.
1918 OPENSSL_EXPORT int SSL_SESSION_to_bytes_for_ticket(const SSL_SESSION *in,
1919                                                    uint8_t **out_data,
1920                                                    size_t *out_len);
1921 
1922 // SSL_SESSION_from_bytes parses |in_len| bytes from |in| as an SSL_SESSION. It
1923 // returns a newly-allocated |SSL_SESSION| on success or NULL on error.
1924 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_from_bytes(
1925     const uint8_t *in, size_t in_len, const SSL_CTX *ctx);
1926 
1927 // SSL_SESSION_get_version returns a string describing the TLS or DTLS version
1928 // |session| was established at. For example, "TLSv1.2" or "DTLSv1".
1929 OPENSSL_EXPORT const char *SSL_SESSION_get_version(const SSL_SESSION *session);
1930 
1931 // SSL_SESSION_get_protocol_version returns the TLS or DTLS version |session|
1932 // was established at.
1933 OPENSSL_EXPORT uint16_t
1934 SSL_SESSION_get_protocol_version(const SSL_SESSION *session);
1935 
1936 // SSL_SESSION_set_protocol_version sets |session|'s TLS or DTLS version to
1937 // |version|. This may be useful when writing tests but should otherwise not be
1938 // used. It returns one on success and zero on error.
1939 OPENSSL_EXPORT int SSL_SESSION_set_protocol_version(SSL_SESSION *session,
1940                                                     uint16_t version);
1941 
1942 // SSL_MAX_SSL_SESSION_ID_LENGTH is the maximum length of an SSL session ID.
1943 #define SSL_MAX_SSL_SESSION_ID_LENGTH 32
1944 
1945 // SSL_SESSION_get_id returns a pointer to a buffer containing |session|'s
1946 // session ID and sets |*out_len| to its length.
1947 //
1948 // This function should only be used for implementing a TLS session cache. TLS
1949 // sessions are not suitable for application-level session state, and a session
1950 // ID is an implementation detail of the TLS resumption handshake mechanism. Not
1951 // all resumption flows use session IDs, and not all connections within an
1952 // application-level session will reuse TLS sessions.
1953 //
1954 // To determine if resumption occurred, use |SSL_session_reused| instead.
1955 // Comparing session IDs will not give the right result in all cases.
1956 //
1957 // As a workaround for some broken applications, BoringSSL sometimes synthesizes
1958 // arbitrary session IDs for non-ID-based sessions. This behavior may be
1959 // removed in the future.
1960 OPENSSL_EXPORT const uint8_t *SSL_SESSION_get_id(const SSL_SESSION *session,
1961                                                  unsigned *out_len);
1962 
1963 // SSL_SESSION_set1_id sets |session|'s session ID to |sid|, It returns one on
1964 // success and zero on error. This function may be useful in writing tests but
1965 // otherwise should not be used.
1966 OPENSSL_EXPORT int SSL_SESSION_set1_id(SSL_SESSION *session, const uint8_t *sid,
1967                                        size_t sid_len);
1968 
1969 // SSL_SESSION_get_time returns the time at which |session| was established in
1970 // seconds since the UNIX epoch.
1971 OPENSSL_EXPORT uint64_t SSL_SESSION_get_time(const SSL_SESSION *session);
1972 
1973 // SSL_SESSION_get_timeout returns the lifetime of |session| in seconds.
1974 OPENSSL_EXPORT uint32_t SSL_SESSION_get_timeout(const SSL_SESSION *session);
1975 
1976 // SSL_SESSION_get0_peer returns the peer leaf certificate stored in
1977 // |session|.
1978 //
1979 // TODO(davidben): This should return a const X509 *.
1980 OPENSSL_EXPORT X509 *SSL_SESSION_get0_peer(const SSL_SESSION *session);
1981 
1982 // SSL_SESSION_get0_peer_certificates returns the peer certificate chain stored
1983 // in |session|, or NULL if the peer did not use certificates. This is the
1984 // unverified list of certificates as sent by the peer, not the final chain
1985 // built during verification. The caller does not take ownership of the result.
1986 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER) *
1987     SSL_SESSION_get0_peer_certificates(const SSL_SESSION *session);
1988 
1989 // SSL_SESSION_get0_signed_cert_timestamp_list sets |*out| and |*out_len| to
1990 // point to |*out_len| bytes of SCT information stored in |session|. This is
1991 // only valid for client sessions. The SCT information is a
1992 // SignedCertificateTimestampList (including the two leading length bytes). See
1993 // https://tools.ietf.org/html/rfc6962#section-3.3 If no SCT was received then
1994 // |*out_len| will be zero on return.
1995 //
1996 // WARNING: the returned data is not guaranteed to be well formed.
1997 OPENSSL_EXPORT void SSL_SESSION_get0_signed_cert_timestamp_list(
1998     const SSL_SESSION *session, const uint8_t **out, size_t *out_len);
1999 
2000 // SSL_SESSION_get0_ocsp_response sets |*out| and |*out_len| to point to
2001 // |*out_len| bytes of an OCSP response from the server. This is the DER
2002 // encoding of an OCSPResponse type as defined in RFC 2560.
2003 //
2004 // WARNING: the returned data is not guaranteed to be well formed.
2005 OPENSSL_EXPORT void SSL_SESSION_get0_ocsp_response(const SSL_SESSION *session,
2006                                                    const uint8_t **out,
2007                                                    size_t *out_len);
2008 
2009 // SSL_MAX_MASTER_KEY_LENGTH is the maximum length of a master secret.
2010 #define SSL_MAX_MASTER_KEY_LENGTH 48
2011 
2012 // SSL_SESSION_get_master_key writes up to |max_out| bytes of |session|'s secret
2013 // to |out| and returns the number of bytes written. If |max_out| is zero, it
2014 // returns the size of the secret.
2015 OPENSSL_EXPORT size_t SSL_SESSION_get_master_key(const SSL_SESSION *session,
2016                                                  uint8_t *out, size_t max_out);
2017 
2018 // SSL_SESSION_set_time sets |session|'s creation time to |time| and returns
2019 // |time|. This function may be useful in writing tests but otherwise should not
2020 // be used.
2021 OPENSSL_EXPORT uint64_t SSL_SESSION_set_time(SSL_SESSION *session,
2022                                              uint64_t time);
2023 
2024 // SSL_SESSION_set_timeout sets |session|'s timeout to |timeout| and returns
2025 // one. This function may be useful in writing tests but otherwise should not
2026 // be used.
2027 OPENSSL_EXPORT uint32_t SSL_SESSION_set_timeout(SSL_SESSION *session,
2028                                                 uint32_t timeout);
2029 
2030 // SSL_SESSION_get0_id_context returns a pointer to a buffer containing
2031 // |session|'s session ID context (see |SSL_CTX_set_session_id_context|) and
2032 // sets |*out_len| to its length.
2033 OPENSSL_EXPORT const uint8_t *SSL_SESSION_get0_id_context(
2034     const SSL_SESSION *session, unsigned *out_len);
2035 
2036 // SSL_SESSION_set1_id_context sets |session|'s session ID context (see
2037 // |SSL_CTX_set_session_id_context|) to |sid_ctx|. It returns one on success and
2038 // zero on error. This function may be useful in writing tests but otherwise
2039 // should not be used.
2040 OPENSSL_EXPORT int SSL_SESSION_set1_id_context(SSL_SESSION *session,
2041                                                const uint8_t *sid_ctx,
2042                                                size_t sid_ctx_len);
2043 
2044 // SSL_SESSION_should_be_single_use returns one if |session| should be
2045 // single-use (TLS 1.3 and later) and zero otherwise.
2046 //
2047 // If this function returns one, clients retain multiple sessions and use each
2048 // only once. This prevents passive observers from correlating connections with
2049 // tickets. See RFC 8446, appendix C.4. If it returns zero, |session| cannot be
2050 // used without leaking a correlator.
2051 OPENSSL_EXPORT int SSL_SESSION_should_be_single_use(const SSL_SESSION *session);
2052 
2053 // SSL_SESSION_is_resumable returns one if |session| is complete and contains a
2054 // session ID or ticket. It returns zero otherwise. Note this function does not
2055 // ensure |session| will be resumed. It may be expired, dropped by the server,
2056 // or associated with incompatible parameters.
2057 OPENSSL_EXPORT int SSL_SESSION_is_resumable(const SSL_SESSION *session);
2058 
2059 // SSL_SESSION_has_ticket returns one if |session| has a ticket and zero
2060 // otherwise.
2061 OPENSSL_EXPORT int SSL_SESSION_has_ticket(const SSL_SESSION *session);
2062 
2063 // SSL_SESSION_get0_ticket sets |*out_ticket| and |*out_len| to |session|'s
2064 // ticket, or NULL and zero if it does not have one. |out_ticket| may be NULL
2065 // if only the ticket length is needed.
2066 OPENSSL_EXPORT void SSL_SESSION_get0_ticket(const SSL_SESSION *session,
2067                                             const uint8_t **out_ticket,
2068                                             size_t *out_len);
2069 
2070 // SSL_SESSION_set_ticket sets |session|'s ticket to |ticket|. It returns one on
2071 // success and zero on error. This function may be useful in writing tests but
2072 // otherwise should not be used.
2073 OPENSSL_EXPORT int SSL_SESSION_set_ticket(SSL_SESSION *session,
2074                                           const uint8_t *ticket,
2075                                           size_t ticket_len);
2076 
2077 // SSL_SESSION_get_ticket_lifetime_hint returns ticket lifetime hint of
2078 // |session| in seconds or zero if none was set.
2079 OPENSSL_EXPORT uint32_t
2080 SSL_SESSION_get_ticket_lifetime_hint(const SSL_SESSION *session);
2081 
2082 // SSL_SESSION_get0_cipher returns the cipher negotiated by the connection which
2083 // established |session|.
2084 //
2085 // Note that, in TLS 1.3, there is no guarantee that resumptions with |session|
2086 // will use that cipher. Prefer calling |SSL_get_current_cipher| on the |SSL|
2087 // instead.
2088 OPENSSL_EXPORT const SSL_CIPHER *SSL_SESSION_get0_cipher(
2089     const SSL_SESSION *session);
2090 
2091 // SSL_SESSION_has_peer_sha256 returns one if |session| has a SHA-256 hash of
2092 // the peer's certificate retained and zero if the peer did not present a
2093 // certificate or if this was not enabled when |session| was created. See also
2094 // |SSL_CTX_set_retain_only_sha256_of_client_certs|.
2095 OPENSSL_EXPORT int SSL_SESSION_has_peer_sha256(const SSL_SESSION *session);
2096 
2097 // SSL_SESSION_get0_peer_sha256 sets |*out_ptr| and |*out_len| to the SHA-256
2098 // hash of the peer certificate retained in |session|, or NULL and zero if it
2099 // does not have one. See also |SSL_CTX_set_retain_only_sha256_of_client_certs|.
2100 OPENSSL_EXPORT void SSL_SESSION_get0_peer_sha256(const SSL_SESSION *session,
2101                                                  const uint8_t **out_ptr,
2102                                                  size_t *out_len);
2103 
2104 
2105 // Session caching.
2106 //
2107 // Session caching allows connections to be established more efficiently based
2108 // on saved parameters from a previous connection, called a session (see
2109 // |SSL_SESSION|). The client offers a saved session, using an opaque identifier
2110 // from a previous connection. The server may accept the session, if it has the
2111 // parameters available. Otherwise, it will decline and continue with a full
2112 // handshake.
2113 //
2114 // This requires both the client and the server to retain session state. A
2115 // client does so with a stateful session cache. A server may do the same or, if
2116 // supported by both sides, statelessly using session tickets. For more
2117 // information on the latter, see the next section.
2118 //
2119 // For a server, the library implements a built-in internal session cache as an
2120 // in-memory hash table. Servers may also use |SSL_CTX_sess_set_get_cb| and
2121 // |SSL_CTX_sess_set_new_cb| to implement a custom external session cache. In
2122 // particular, this may be used to share a session cache between multiple
2123 // servers in a large deployment. An external cache may be used in addition to
2124 // or instead of the internal one. Use |SSL_CTX_set_session_cache_mode| to
2125 // toggle the internal cache.
2126 //
2127 // For a client, the only option is an external session cache. Clients may use
2128 // |SSL_CTX_sess_set_new_cb| to register a callback for when new sessions are
2129 // available. These may be cached and, in subsequent compatible connections,
2130 // configured with |SSL_set_session|.
2131 //
2132 // Note that offering or accepting a session short-circuits certificate
2133 // verification and most parameter negotiation. Resuming sessions across
2134 // different contexts may result in security failures and surprising
2135 // behavior. For a typical client, this means sessions for different hosts must
2136 // be cached under different keys. A client that connects to the same host with,
2137 // e.g., different cipher suite settings or client certificates should also use
2138 // separate session caches between those contexts. Servers should also partition
2139 // session caches between SNI hosts with |SSL_CTX_set_session_id_context|.
2140 //
2141 // Note also, in TLS 1.2 and earlier, offering sessions allows passive observers
2142 // to correlate different client connections. TLS 1.3 and later fix this,
2143 // provided clients use sessions at most once. Session caches are managed by the
2144 // caller in BoringSSL, so this must be implemented externally. See
2145 // |SSL_SESSION_should_be_single_use| for details.
2146 
2147 // SSL_SESS_CACHE_OFF disables all session caching.
2148 #define SSL_SESS_CACHE_OFF 0x0000
2149 
2150 // SSL_SESS_CACHE_CLIENT enables session caching for a client. The internal
2151 // cache is never used on a client, so this only enables the callbacks.
2152 #define SSL_SESS_CACHE_CLIENT 0x0001
2153 
2154 // SSL_SESS_CACHE_SERVER enables session caching for a server.
2155 #define SSL_SESS_CACHE_SERVER 0x0002
2156 
2157 // SSL_SESS_CACHE_BOTH enables session caching for both client and server.
2158 #define SSL_SESS_CACHE_BOTH (SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_SERVER)
2159 
2160 // SSL_SESS_CACHE_NO_AUTO_CLEAR disables automatically calling
2161 // |SSL_CTX_flush_sessions| every 255 connections.
2162 #define SSL_SESS_CACHE_NO_AUTO_CLEAR 0x0080
2163 
2164 // SSL_SESS_CACHE_NO_INTERNAL_LOOKUP, on a server, disables looking up a session
2165 // from the internal session cache.
2166 #define SSL_SESS_CACHE_NO_INTERNAL_LOOKUP 0x0100
2167 
2168 // SSL_SESS_CACHE_NO_INTERNAL_STORE, on a server, disables storing sessions in
2169 // the internal session cache.
2170 #define SSL_SESS_CACHE_NO_INTERNAL_STORE 0x0200
2171 
2172 // SSL_SESS_CACHE_NO_INTERNAL, on a server, disables the internal session
2173 // cache.
2174 #define SSL_SESS_CACHE_NO_INTERNAL \
2175     (SSL_SESS_CACHE_NO_INTERNAL_LOOKUP | SSL_SESS_CACHE_NO_INTERNAL_STORE)
2176 
2177 // SSL_CTX_set_session_cache_mode sets the session cache mode bits for |ctx| to
2178 // |mode|. It returns the previous value.
2179 OPENSSL_EXPORT int SSL_CTX_set_session_cache_mode(SSL_CTX *ctx, int mode);
2180 
2181 // SSL_CTX_get_session_cache_mode returns the session cache mode bits for
2182 // |ctx|
2183 OPENSSL_EXPORT int SSL_CTX_get_session_cache_mode(const SSL_CTX *ctx);
2184 
2185 // SSL_set_session, for a client, configures |ssl| to offer to resume |session|
2186 // in the initial handshake and returns one. The caller retains ownership of
2187 // |session|. Note that configuring a session assumes the authentication in the
2188 // session is valid. For callers that wish to revalidate the session before
2189 // offering, see |SSL_SESSION_get0_peer_certificates|,
2190 // |SSL_SESSION_get0_signed_cert_timestamp_list|, and
2191 // |SSL_SESSION_get0_ocsp_response|.
2192 //
2193 // It is an error to call this function after the handshake has begun.
2194 OPENSSL_EXPORT int SSL_set_session(SSL *ssl, SSL_SESSION *session);
2195 
2196 // SSL_DEFAULT_SESSION_TIMEOUT is the default lifetime, in seconds, of a
2197 // session in TLS 1.2 or earlier. This is how long we are willing to use the
2198 // secret to encrypt traffic without fresh key material.
2199 #define SSL_DEFAULT_SESSION_TIMEOUT (2 * 60 * 60)
2200 
2201 // SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT is the default lifetime, in seconds, of a
2202 // session for TLS 1.3 psk_dhe_ke. This is how long we are willing to use the
2203 // secret as an authenticator.
2204 #define SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT (2 * 24 * 60 * 60)
2205 
2206 // SSL_DEFAULT_SESSION_AUTH_TIMEOUT is the default non-renewable lifetime, in
2207 // seconds, of a TLS 1.3 session. This is how long we are willing to trust the
2208 // signature in the initial handshake.
2209 #define SSL_DEFAULT_SESSION_AUTH_TIMEOUT (7 * 24 * 60 * 60)
2210 
2211 // SSL_CTX_set_timeout sets the lifetime, in seconds, of TLS 1.2 (or earlier)
2212 // sessions created in |ctx| to |timeout|.
2213 OPENSSL_EXPORT uint32_t SSL_CTX_set_timeout(SSL_CTX *ctx, uint32_t timeout);
2214 
2215 // SSL_CTX_set_session_psk_dhe_timeout sets the lifetime, in seconds, of TLS 1.3
2216 // sessions created in |ctx| to |timeout|.
2217 OPENSSL_EXPORT void SSL_CTX_set_session_psk_dhe_timeout(SSL_CTX *ctx,
2218                                                         uint32_t timeout);
2219 
2220 // SSL_CTX_get_timeout returns the lifetime, in seconds, of TLS 1.2 (or earlier)
2221 // sessions created in |ctx|.
2222 OPENSSL_EXPORT uint32_t SSL_CTX_get_timeout(const SSL_CTX *ctx);
2223 
2224 // SSL_MAX_SID_CTX_LENGTH is the maximum length of a session ID context.
2225 #define SSL_MAX_SID_CTX_LENGTH 32
2226 
2227 // SSL_CTX_set_session_id_context sets |ctx|'s session ID context to |sid_ctx|.
2228 // It returns one on success and zero on error. The session ID context is an
2229 // application-defined opaque byte string. A session will not be used in a
2230 // connection without a matching session ID context.
2231 //
2232 // For a server, if |SSL_VERIFY_PEER| is enabled, it is an error to not set a
2233 // session ID context.
2234 OPENSSL_EXPORT int SSL_CTX_set_session_id_context(SSL_CTX *ctx,
2235                                                   const uint8_t *sid_ctx,
2236                                                   size_t sid_ctx_len);
2237 
2238 // SSL_set_session_id_context sets |ssl|'s session ID context to |sid_ctx|. It
2239 // returns one on success and zero on error. See also
2240 // |SSL_CTX_set_session_id_context|.
2241 OPENSSL_EXPORT int SSL_set_session_id_context(SSL *ssl, const uint8_t *sid_ctx,
2242                                               size_t sid_ctx_len);
2243 
2244 // SSL_get0_session_id_context returns a pointer to |ssl|'s session ID context
2245 // and sets |*out_len| to its length.  It returns NULL on error.
2246 OPENSSL_EXPORT const uint8_t *SSL_get0_session_id_context(const SSL *ssl,
2247                                                           size_t *out_len);
2248 
2249 // SSL_SESSION_CACHE_MAX_SIZE_DEFAULT is the default maximum size of a session
2250 // cache.
2251 #define SSL_SESSION_CACHE_MAX_SIZE_DEFAULT (1024 * 20)
2252 
2253 // SSL_CTX_sess_set_cache_size sets the maximum size of |ctx|'s internal session
2254 // cache to |size|. It returns the previous value.
2255 OPENSSL_EXPORT unsigned long SSL_CTX_sess_set_cache_size(SSL_CTX *ctx,
2256                                                          unsigned long size);
2257 
2258 // SSL_CTX_sess_get_cache_size returns the maximum size of |ctx|'s internal
2259 // session cache.
2260 OPENSSL_EXPORT unsigned long SSL_CTX_sess_get_cache_size(const SSL_CTX *ctx);
2261 
2262 // SSL_CTX_sess_number returns the number of sessions in |ctx|'s internal
2263 // session cache.
2264 OPENSSL_EXPORT size_t SSL_CTX_sess_number(const SSL_CTX *ctx);
2265 
2266 // SSL_CTX_add_session inserts |session| into |ctx|'s internal session cache. It
2267 // returns one on success and zero on error or if |session| is already in the
2268 // cache. The caller retains its reference to |session|.
2269 OPENSSL_EXPORT int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *session);
2270 
2271 // SSL_CTX_remove_session removes |session| from |ctx|'s internal session cache.
2272 // It returns one on success and zero if |session| was not in the cache.
2273 OPENSSL_EXPORT int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session);
2274 
2275 // SSL_CTX_flush_sessions removes all sessions from |ctx| which have expired as
2276 // of time |time|. If |time| is zero, all sessions are removed.
2277 OPENSSL_EXPORT void SSL_CTX_flush_sessions(SSL_CTX *ctx, uint64_t time);
2278 
2279 // SSL_CTX_sess_set_new_cb sets the callback to be called when a new session is
2280 // established and ready to be cached. If the session cache is disabled (the
2281 // appropriate one of |SSL_SESS_CACHE_CLIENT| or |SSL_SESS_CACHE_SERVER| is
2282 // unset), the callback is not called.
2283 //
2284 // The callback is passed a reference to |session|. It returns one if it takes
2285 // ownership (and then calls |SSL_SESSION_free| when done) and zero otherwise. A
2286 // consumer which places |session| into an in-memory cache will likely return
2287 // one, with the cache calling |SSL_SESSION_free|. A consumer which serializes
2288 // |session| with |SSL_SESSION_to_bytes| may not need to retain |session| and
2289 // will likely return zero. Returning one is equivalent to calling
2290 // |SSL_SESSION_up_ref| and then returning zero.
2291 //
2292 // Note: For a client, the callback may be called on abbreviated handshakes if a
2293 // ticket is renewed. Further, it may not be called until some time after
2294 // |SSL_do_handshake| or |SSL_connect| completes if False Start is enabled. Thus
2295 // it's recommended to use this callback over calling |SSL_get_session| on
2296 // handshake completion.
2297 OPENSSL_EXPORT void SSL_CTX_sess_set_new_cb(
2298     SSL_CTX *ctx, int (*new_session_cb)(SSL *ssl, SSL_SESSION *session));
2299 
2300 // SSL_CTX_sess_get_new_cb returns the callback set by
2301 // |SSL_CTX_sess_set_new_cb|.
2302 OPENSSL_EXPORT int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(
2303     SSL *ssl, SSL_SESSION *session);
2304 
2305 // SSL_CTX_sess_set_remove_cb sets a callback which is called when a session is
2306 // removed from the internal session cache.
2307 //
2308 // TODO(davidben): What is the point of this callback? It seems useless since it
2309 // only fires on sessions in the internal cache.
2310 OPENSSL_EXPORT void SSL_CTX_sess_set_remove_cb(
2311     SSL_CTX *ctx,
2312     void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *session));
2313 
2314 // SSL_CTX_sess_get_remove_cb returns the callback set by
2315 // |SSL_CTX_sess_set_remove_cb|.
2316 OPENSSL_EXPORT void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(
2317     SSL_CTX *ctx, SSL_SESSION *session);
2318 
2319 // SSL_CTX_sess_set_get_cb sets a callback to look up a session by ID for a
2320 // server. The callback is passed the session ID and should return a matching
2321 // |SSL_SESSION| or NULL if not found. It should set |*out_copy| to zero and
2322 // return a new reference to the session. This callback is not used for a
2323 // client.
2324 //
2325 // For historical reasons, if |*out_copy| is set to one (default), the SSL
2326 // library will take a new reference to the returned |SSL_SESSION|, expecting
2327 // the callback to return a non-owning pointer. This is not recommended. If
2328 // |ctx| and thus the callback is used on multiple threads, the session may be
2329 // removed and invalidated before the SSL library calls |SSL_SESSION_up_ref|,
2330 // whereas the callback may synchronize internally.
2331 //
2332 // To look up a session asynchronously, the callback may return
2333 // |SSL_magic_pending_session_ptr|. See the documentation for that function and
2334 // |SSL_ERROR_PENDING_SESSION|.
2335 //
2336 // If the internal session cache is enabled, the callback is only consulted if
2337 // the internal cache does not return a match.
2338 OPENSSL_EXPORT void SSL_CTX_sess_set_get_cb(
2339     SSL_CTX *ctx, SSL_SESSION *(*get_session_cb)(SSL *ssl, const uint8_t *id,
2340                                                  int id_len, int *out_copy));
2341 
2342 // SSL_CTX_sess_get_get_cb returns the callback set by
2343 // |SSL_CTX_sess_set_get_cb|.
2344 OPENSSL_EXPORT SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(
2345     SSL *ssl, const uint8_t *id, int id_len, int *out_copy);
2346 
2347 // SSL_magic_pending_session_ptr returns a magic |SSL_SESSION|* which indicates
2348 // that the session isn't currently unavailable. |SSL_get_error| will then
2349 // return |SSL_ERROR_PENDING_SESSION| and the handshake can be retried later
2350 // when the lookup has completed.
2351 OPENSSL_EXPORT SSL_SESSION *SSL_magic_pending_session_ptr(void);
2352 
2353 
2354 // Session tickets.
2355 //
2356 // Session tickets, from RFC 5077, allow session resumption without server-side
2357 // state. The server maintains a secret ticket key and sends the client opaque
2358 // encrypted session parameters, called a ticket. When offering the session, the
2359 // client sends the ticket which the server decrypts to recover session state.
2360 // Session tickets are enabled by default but may be disabled with
2361 // |SSL_OP_NO_TICKET|.
2362 //
2363 // On the client, ticket-based sessions use the same APIs as ID-based tickets.
2364 // Callers do not need to handle them differently.
2365 //
2366 // On the server, tickets are encrypted and authenticated with a secret key.
2367 // By default, an |SSL_CTX| will manage session ticket encryption keys by
2368 // generating them internally and rotating every 48 hours. Tickets are minted
2369 // and processed transparently. The following functions may be used to configure
2370 // a persistent key or implement more custom behavior, including key rotation
2371 // and sharing keys between multiple servers in a large deployment. There are
2372 // three levels of customisation possible:
2373 //
2374 // 1) One can simply set the keys with |SSL_CTX_set_tlsext_ticket_keys|.
2375 // 2) One can configure an |EVP_CIPHER_CTX| and |HMAC_CTX| directly for
2376 //    encryption and authentication.
2377 // 3) One can configure an |SSL_TICKET_AEAD_METHOD| to have more control
2378 //    and the option of asynchronous decryption.
2379 //
2380 // An attacker that compromises a server's session ticket key can impersonate
2381 // the server and, prior to TLS 1.3, retroactively decrypt all application
2382 // traffic from sessions using that ticket key. Thus ticket keys must be
2383 // regularly rotated for forward secrecy. Note the default key is rotated
2384 // automatically once every 48 hours but manually configured keys are not.
2385 
2386 // SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL is the interval with which the
2387 // default session ticket encryption key is rotated, if in use. If any
2388 // non-default ticket encryption mechanism is configured, automatic rotation is
2389 // disabled.
2390 #define SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL (2 * 24 * 60 * 60)
2391 
2392 // SSL_CTX_get_tlsext_ticket_keys writes |ctx|'s session ticket key material to
2393 // |len| bytes of |out|. It returns one on success and zero if |len| is not
2394 // 48. If |out| is NULL, it returns 48 instead.
2395 OPENSSL_EXPORT int SSL_CTX_get_tlsext_ticket_keys(SSL_CTX *ctx, void *out,
2396                                                   size_t len);
2397 
2398 // SSL_CTX_set_tlsext_ticket_keys sets |ctx|'s session ticket key material to
2399 // |len| bytes of |in|. It returns one on success and zero if |len| is not
2400 // 48. If |in| is NULL, it returns 48 instead.
2401 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_keys(SSL_CTX *ctx, const void *in,
2402                                                   size_t len);
2403 
2404 // SSL_TICKET_KEY_NAME_LEN is the length of the key name prefix of a session
2405 // ticket.
2406 #define SSL_TICKET_KEY_NAME_LEN 16
2407 
2408 // SSL_CTX_set_tlsext_ticket_key_cb sets the ticket callback to |callback| and
2409 // returns one. |callback| will be called when encrypting a new ticket and when
2410 // decrypting a ticket from the client.
2411 //
2412 // In both modes, |ctx| and |hmac_ctx| will already have been initialized with
2413 // |EVP_CIPHER_CTX_init| and |HMAC_CTX_init|, respectively. |callback|
2414 // configures |hmac_ctx| with an HMAC digest and key, and configures |ctx|
2415 // for encryption or decryption, based on the mode.
2416 //
2417 // When encrypting a new ticket, |encrypt| will be one. It writes a public
2418 // 16-byte key name to |key_name| and a fresh IV to |iv|. The output IV length
2419 // must match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
2420 // |callback| returns 1 on success and -1 on error.
2421 //
2422 // When decrypting a ticket, |encrypt| will be zero. |key_name| will point to a
2423 // 16-byte key name and |iv| points to an IV. The length of the IV consumed must
2424 // match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
2425 // |callback| returns -1 to abort the handshake, 0 if decrypting the ticket
2426 // failed, and 1 or 2 on success. If it returns 2, the ticket will be renewed.
2427 // This may be used to re-key the ticket.
2428 //
2429 // WARNING: |callback| wildly breaks the usual return value convention and is
2430 // called in two different modes.
2431 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_key_cb(
2432     SSL_CTX *ctx, int (*callback)(SSL *ssl, uint8_t *key_name, uint8_t *iv,
2433                                   EVP_CIPHER_CTX *ctx, HMAC_CTX *hmac_ctx,
2434                                   int encrypt));
2435 
2436 // ssl_ticket_aead_result_t enumerates the possible results from decrypting a
2437 // ticket with an |SSL_TICKET_AEAD_METHOD|.
2438 enum ssl_ticket_aead_result_t BORINGSSL_ENUM_INT {
2439   // ssl_ticket_aead_success indicates that the ticket was successfully
2440   // decrypted.
2441   ssl_ticket_aead_success,
2442   // ssl_ticket_aead_retry indicates that the operation could not be
2443   // immediately completed and must be reattempted, via |open|, at a later
2444   // point.
2445   ssl_ticket_aead_retry,
2446   // ssl_ticket_aead_ignore_ticket indicates that the ticket should be ignored
2447   // (i.e. is corrupt or otherwise undecryptable).
2448   ssl_ticket_aead_ignore_ticket,
2449   // ssl_ticket_aead_error indicates that a fatal error occured and the
2450   // handshake should be terminated.
2451   ssl_ticket_aead_error,
2452 };
2453 
2454 // ssl_ticket_aead_method_st (aka |SSL_TICKET_AEAD_METHOD|) contains methods
2455 // for encrypting and decrypting session tickets.
2456 struct ssl_ticket_aead_method_st {
2457   // max_overhead returns the maximum number of bytes of overhead that |seal|
2458   // may add.
2459   size_t (*max_overhead)(SSL *ssl);
2460 
2461   // seal encrypts and authenticates |in_len| bytes from |in|, writes, at most,
2462   // |max_out_len| bytes to |out|, and puts the number of bytes written in
2463   // |*out_len|. The |in| and |out| buffers may be equal but will not otherwise
2464   // alias. It returns one on success or zero on error.
2465   int (*seal)(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out_len,
2466               const uint8_t *in, size_t in_len);
2467 
2468   // open authenticates and decrypts |in_len| bytes from |in|, writes, at most,
2469   // |max_out_len| bytes of plaintext to |out|, and puts the number of bytes
2470   // written in |*out_len|. The |in| and |out| buffers may be equal but will
2471   // not otherwise alias. See |ssl_ticket_aead_result_t| for details of the
2472   // return values. In the case that a retry is indicated, the caller should
2473   // arrange for the high-level operation on |ssl| to be retried when the
2474   // operation is completed, which will result in another call to |open|.
2475   enum ssl_ticket_aead_result_t (*open)(SSL *ssl, uint8_t *out, size_t *out_len,
2476                                         size_t max_out_len, const uint8_t *in,
2477                                         size_t in_len);
2478 };
2479 
2480 // SSL_CTX_set_ticket_aead_method configures a custom ticket AEAD method table
2481 // on |ctx|. |aead_method| must remain valid for the lifetime of |ctx|.
2482 OPENSSL_EXPORT void SSL_CTX_set_ticket_aead_method(
2483     SSL_CTX *ctx, const SSL_TICKET_AEAD_METHOD *aead_method);
2484 
2485 // SSL_process_tls13_new_session_ticket processes an unencrypted TLS 1.3
2486 // NewSessionTicket message from |buf| and returns a resumable |SSL_SESSION|,
2487 // or NULL on error. The caller takes ownership of the returned session and
2488 // must call |SSL_SESSION_free| to free it.
2489 //
2490 // |buf| contains |buf_len| bytes that represents a complete NewSessionTicket
2491 // message including its header, i.e., one byte for the type (0x04) and three
2492 // bytes for the length. |buf| must contain only one such message.
2493 //
2494 // This function may be used to process NewSessionTicket messages in TLS 1.3
2495 // clients that are handling the record layer externally.
2496 OPENSSL_EXPORT SSL_SESSION *SSL_process_tls13_new_session_ticket(
2497     SSL *ssl, const uint8_t *buf, size_t buf_len);
2498 
2499 // SSL_CTX_set_num_tickets configures |ctx| to send |num_tickets| immediately
2500 // after a successful TLS 1.3 handshake as a server. It returns one. Large
2501 // values of |num_tickets| will be capped within the library.
2502 //
2503 // By default, BoringSSL sends two tickets.
2504 OPENSSL_EXPORT int SSL_CTX_set_num_tickets(SSL_CTX *ctx, size_t num_tickets);
2505 
2506 // SSL_CTX_get_num_tickets returns the number of tickets |ctx| will send
2507 // immediately after a successful TLS 1.3 handshake as a server.
2508 OPENSSL_EXPORT size_t SSL_CTX_get_num_tickets(const SSL_CTX *ctx);
2509 
2510 
2511 // Diffie-Hellman groups and ephemeral key exchanges.
2512 //
2513 // Most TLS handshakes (ECDHE cipher suites in TLS 1.2, and all supported TLS
2514 // 1.3 modes) incorporate an ephemeral key exchange, most commonly using
2515 // Elliptic Curve Diffie-Hellman (ECDH), as described in RFC 8422. The key
2516 // exchange algorithm is negotiated separately from the cipher suite, using
2517 // NamedGroup values, which define Diffie-Hellman groups.
2518 //
2519 // Historically, these values were known as "curves", in reference to ECDH, and
2520 // some APIs refer to the original name. RFC 7919 renamed them to "groups" in
2521 // reference to Diffie-Hellman in general. These values are also used to select
2522 // experimental post-quantum KEMs. Though not Diffie-Hellman groups, KEMs can
2523 // fill a similar role in TLS, so they use the same codepoints.
2524 //
2525 // In TLS 1.2, the ECDH values also negotiate elliptic curves used in ECDSA. In
2526 // TLS 1.3 and later, ECDSA curves are part of the signature algorithm. See
2527 // |SSL_SIGN_*|.
2528 
2529 // SSL_GROUP_* define TLS group IDs.
2530 #define SSL_GROUP_SECP224R1 21
2531 #define SSL_GROUP_SECP256R1 23
2532 #define SSL_GROUP_SECP384R1 24
2533 #define SSL_GROUP_SECP521R1 25
2534 #define SSL_GROUP_X25519 29
2535 #define SSL_GROUP_X25519_KYBER768_DRAFT00 0x6399
2536 
2537 // SSL_CTX_set1_group_ids sets the preferred groups for |ctx| to |group_ids|.
2538 // Each element of |group_ids| should be one of the |SSL_GROUP_*| constants. It
2539 // returns one on success and zero on failure.
2540 OPENSSL_EXPORT int SSL_CTX_set1_group_ids(SSL_CTX *ctx,
2541                                           const uint16_t *group_ids,
2542                                           size_t num_group_ids);
2543 
2544 // SSL_set1_group_ids sets the preferred groups for |ssl| to |group_ids|. Each
2545 // element of |group_ids| should be one of the |SSL_GROUP_*| constants. It
2546 // returns one on success and zero on failure.
2547 OPENSSL_EXPORT int SSL_set1_group_ids(SSL *ssl, const uint16_t *group_ids,
2548                                       size_t num_group_ids);
2549 
2550 // SSL_get_group_id returns the ID of the group used by |ssl|'s most recently
2551 // completed handshake, or 0 if not applicable.
2552 OPENSSL_EXPORT uint16_t SSL_get_group_id(const SSL *ssl);
2553 
2554 // SSL_get_group_name returns a human-readable name for the group specified by
2555 // the given TLS group ID, or NULL if the group is unknown.
2556 OPENSSL_EXPORT const char *SSL_get_group_name(uint16_t group_id);
2557 
2558 // SSL_get_all_group_names outputs a list of possible strings
2559 // |SSL_get_group_name| may return in this version of BoringSSL. It writes at
2560 // most |max_out| entries to |out| and returns the total number it would have
2561 // written, if |max_out| had been large enough. |max_out| may be initially set
2562 // to zero to size the output.
2563 //
2564 // This function is only intended to help initialize tables in callers that want
2565 // possible strings pre-declared. This list would not be suitable to set a list
2566 // of supported features. It is in no particular order, and may contain
2567 // placeholder, experimental, or deprecated values that do not apply to every
2568 // caller. Future versions of BoringSSL may also return strings not in this
2569 // list, so this does not apply if, say, sending strings across services.
2570 OPENSSL_EXPORT size_t SSL_get_all_group_names(const char **out, size_t max_out);
2571 
2572 // The following APIs also configure Diffie-Hellman groups, but use |NID_*|
2573 // constants instead of |SSL_GROUP_*| constants. These are provided for OpenSSL
2574 // compatibility. Where NIDs are unstable constants specific to OpenSSL and
2575 // BoringSSL, group IDs are defined by the TLS protocol. Prefer the group ID
2576 // representation if storing persistently, or exporting to another process or
2577 // library.
2578 
2579 // SSL_CTX_set1_groups sets the preferred groups for |ctx| to be |groups|. Each
2580 // element of |groups| should be a |NID_*| constant from nid.h. It returns one
2581 // on success and zero on failure.
2582 OPENSSL_EXPORT int SSL_CTX_set1_groups(SSL_CTX *ctx, const int *groups,
2583                                        size_t num_groups);
2584 
2585 // SSL_set1_groups sets the preferred groups for |ssl| to be |groups|. Each
2586 // element of |groups| should be a |NID_*| constant from nid.h. It returns one
2587 // on success and zero on failure.
2588 OPENSSL_EXPORT int SSL_set1_groups(SSL *ssl, const int *groups,
2589                                    size_t num_groups);
2590 
2591 // SSL_CTX_set1_groups_list decodes |groups| as a colon-separated list of group
2592 // names (e.g. "X25519" or "P-256") and sets |ctx|'s preferred groups to the
2593 // result. It returns one on success and zero on failure.
2594 OPENSSL_EXPORT int SSL_CTX_set1_groups_list(SSL_CTX *ctx, const char *groups);
2595 
2596 // SSL_set1_groups_list decodes |groups| as a colon-separated list of group
2597 // names (e.g. "X25519" or "P-256") and sets |ssl|'s preferred groups to the
2598 // result. It returns one on success and zero on failure.
2599 OPENSSL_EXPORT int SSL_set1_groups_list(SSL *ssl, const char *groups);
2600 
2601 // SSL_get_negotiated_group returns the NID of the group used by |ssl|'s most
2602 // recently completed handshake, or |NID_undef| if not applicable.
2603 OPENSSL_EXPORT int SSL_get_negotiated_group(const SSL *ssl);
2604 
2605 
2606 // Certificate verification.
2607 //
2608 // SSL may authenticate either endpoint with an X.509 certificate. Typically
2609 // this is used to authenticate the server to the client. These functions
2610 // configure certificate verification.
2611 //
2612 // WARNING: By default, certificate verification errors on a client are not
2613 // fatal. See |SSL_VERIFY_NONE| This may be configured with
2614 // |SSL_CTX_set_verify|.
2615 //
2616 // By default clients are anonymous but a server may request a certificate from
2617 // the client by setting |SSL_VERIFY_PEER|.
2618 //
2619 // Many of these functions use OpenSSL's legacy X.509 stack which is
2620 // underdocumented and deprecated, but the replacement isn't ready yet. For
2621 // now, consumers may use the existing stack or bypass it by performing
2622 // certificate verification externally. This may be done with
2623 // |SSL_CTX_set_cert_verify_callback| or by extracting the chain with
2624 // |SSL_get_peer_cert_chain| after the handshake. In the future, functions will
2625 // be added to use the SSL stack without dependency on any part of the legacy
2626 // X.509 and ASN.1 stack.
2627 //
2628 // To augment certificate verification, a client may also enable OCSP stapling
2629 // (RFC 6066) and Certificate Transparency (RFC 6962) extensions.
2630 
2631 // SSL_VERIFY_NONE, on a client, verifies the server certificate but does not
2632 // make errors fatal. The result may be checked with |SSL_get_verify_result|. On
2633 // a server it does not request a client certificate. This is the default.
2634 #define SSL_VERIFY_NONE 0x00
2635 
2636 // SSL_VERIFY_PEER, on a client, makes server certificate errors fatal. On a
2637 // server it requests a client certificate and makes errors fatal. However,
2638 // anonymous clients are still allowed. See
2639 // |SSL_VERIFY_FAIL_IF_NO_PEER_CERT|.
2640 #define SSL_VERIFY_PEER 0x01
2641 
2642 // SSL_VERIFY_FAIL_IF_NO_PEER_CERT configures a server to reject connections if
2643 // the client declines to send a certificate. This flag must be used together
2644 // with |SSL_VERIFY_PEER|, otherwise it won't work.
2645 #define SSL_VERIFY_FAIL_IF_NO_PEER_CERT 0x02
2646 
2647 // SSL_VERIFY_PEER_IF_NO_OBC configures a server to request a client certificate
2648 // if and only if Channel ID is not negotiated.
2649 #define SSL_VERIFY_PEER_IF_NO_OBC 0x04
2650 
2651 // SSL_CTX_set_verify configures certificate verification behavior. |mode| is
2652 // one of the |SSL_VERIFY_*| values defined above. |callback| should be NULL.
2653 //
2654 // If |callback| is non-NULL, it is called as in |X509_STORE_CTX_set_verify_cb|,
2655 // which is a deprecated and fragile mechanism to run the default certificate
2656 // verification process, but suppress individual errors in it. See
2657 // |X509_STORE_CTX_set_verify_cb| for details, If set, the callback may use
2658 // |SSL_get_ex_data_X509_STORE_CTX_idx| with |X509_STORE_CTX_get_ex_data| to
2659 // look up the |SSL| from |store_ctx|.
2660 //
2661 // WARNING: |callback| is not suitable for implementing custom certificate
2662 // check, accepting all certificates, or extracting the certificate after
2663 // verification. It does not replace the default process and is called multiple
2664 // times throughout that process. It is also very difficult to implement this
2665 // callback safely, without inadvertently relying on implementation details or
2666 // making incorrect assumptions about when the callback is called.
2667 //
2668 // Instead, use |SSL_CTX_set_custom_verify| or
2669 // |SSL_CTX_set_cert_verify_callback| to customize certificate verification.
2670 // Those callbacks can inspect the peer-sent chain, call |X509_verify_cert| and
2671 // inspect the result, or perform other operations more straightforwardly.
2672 OPENSSL_EXPORT void SSL_CTX_set_verify(
2673     SSL_CTX *ctx, int mode, int (*callback)(int ok, X509_STORE_CTX *store_ctx));
2674 
2675 // SSL_set_verify configures certificate verification behavior. |mode| is one of
2676 // the |SSL_VERIFY_*| values defined above. |callback| should be NULL.
2677 //
2678 // If |callback| is non-NULL, it is called as in |X509_STORE_CTX_set_verify_cb|,
2679 // which is a deprecated and fragile mechanism to run the default certificate
2680 // verification process, but suppress individual errors in it. See
2681 // |X509_STORE_CTX_set_verify_cb| for details, If set, the callback may use
2682 // |SSL_get_ex_data_X509_STORE_CTX_idx| with |X509_STORE_CTX_get_ex_data| to
2683 // look up the |SSL| from |store_ctx|.
2684 //
2685 // WARNING: |callback| is not suitable for implementing custom certificate
2686 // check, accepting all certificates, or extracting the certificate after
2687 // verification. It does not replace the default process and is called multiple
2688 // times throughout that process. It is also very difficult to implement this
2689 // callback safely, without inadvertently relying on implementation details or
2690 // making incorrect assumptions about when the callback is called.
2691 //
2692 // Instead, use |SSL_set_custom_verify| or |SSL_set_cert_verify_callback| to
2693 // customize certificate verification. Those callbacks can inspect the peer-sent
2694 // chain, call |X509_verify_cert| and inspect the result, or perform other
2695 // operations more straightforwardly.
2696 OPENSSL_EXPORT void SSL_set_verify(SSL *ssl, int mode,
2697                                    int (*callback)(int ok,
2698                                                    X509_STORE_CTX *store_ctx));
2699 
2700 enum ssl_verify_result_t BORINGSSL_ENUM_INT {
2701   ssl_verify_ok,
2702   ssl_verify_invalid,
2703   ssl_verify_retry,
2704 };
2705 
2706 // SSL_CTX_set_custom_verify configures certificate verification. |mode| is one
2707 // of the |SSL_VERIFY_*| values defined above. |callback| performs the
2708 // certificate verification.
2709 //
2710 // The callback may call |SSL_get0_peer_certificates| for the certificate chain
2711 // to validate. The callback should return |ssl_verify_ok| if the certificate is
2712 // valid. If the certificate is invalid, the callback should return
2713 // |ssl_verify_invalid| and optionally set |*out_alert| to an alert to send to
2714 // the peer. Some useful alerts include |SSL_AD_CERTIFICATE_EXPIRED|,
2715 // |SSL_AD_CERTIFICATE_REVOKED|, |SSL_AD_UNKNOWN_CA|, |SSL_AD_BAD_CERTIFICATE|,
2716 // |SSL_AD_CERTIFICATE_UNKNOWN|, and |SSL_AD_INTERNAL_ERROR|. See RFC 5246
2717 // section 7.2.2 for their precise meanings. If unspecified,
2718 // |SSL_AD_CERTIFICATE_UNKNOWN| will be sent by default.
2719 //
2720 // To verify a certificate asynchronously, the callback may return
2721 // |ssl_verify_retry|. The handshake will then pause with |SSL_get_error|
2722 // returning |SSL_ERROR_WANT_CERTIFICATE_VERIFY|.
2723 OPENSSL_EXPORT void SSL_CTX_set_custom_verify(
2724     SSL_CTX *ctx, int mode,
2725     enum ssl_verify_result_t (*callback)(SSL *ssl, uint8_t *out_alert));
2726 
2727 // SSL_set_custom_verify behaves like |SSL_CTX_set_custom_verify| but configures
2728 // an individual |SSL|.
2729 OPENSSL_EXPORT void SSL_set_custom_verify(
2730     SSL *ssl, int mode,
2731     enum ssl_verify_result_t (*callback)(SSL *ssl, uint8_t *out_alert));
2732 
2733 // SSL_CTX_get_verify_mode returns |ctx|'s verify mode, set by
2734 // |SSL_CTX_set_verify|.
2735 OPENSSL_EXPORT int SSL_CTX_get_verify_mode(const SSL_CTX *ctx);
2736 
2737 // SSL_get_verify_mode returns |ssl|'s verify mode, set by |SSL_CTX_set_verify|
2738 // or |SSL_set_verify|.  It returns -1 on error.
2739 OPENSSL_EXPORT int SSL_get_verify_mode(const SSL *ssl);
2740 
2741 // SSL_CTX_get_verify_callback returns the callback set by
2742 // |SSL_CTX_set_verify|.
2743 OPENSSL_EXPORT int (*SSL_CTX_get_verify_callback(const SSL_CTX *ctx))(
2744     int ok, X509_STORE_CTX *store_ctx);
2745 
2746 // SSL_get_verify_callback returns the callback set by |SSL_CTX_set_verify| or
2747 // |SSL_set_verify|.
2748 OPENSSL_EXPORT int (*SSL_get_verify_callback(const SSL *ssl))(
2749     int ok, X509_STORE_CTX *store_ctx);
2750 
2751 // SSL_set1_host sets a DNS name that will be required to be present in the
2752 // verified leaf certificate. It returns one on success and zero on error.
2753 //
2754 // Note: unless _some_ name checking is performed, certificate validation is
2755 // ineffective. Simply checking that a host has some certificate from a CA is
2756 // rarely meaningful—you have to check that the CA believed that the host was
2757 // who you expect to be talking to.
2758 //
2759 // By default, both subject alternative names and the subject's common name
2760 // attribute are checked. The latter has long been deprecated, so callers should
2761 // call |SSL_set_hostflags| with |X509_CHECK_FLAG_NEVER_CHECK_SUBJECT| to use
2762 // the standard behavior. https://crbug.com/boringssl/464 tracks fixing the
2763 // default.
2764 OPENSSL_EXPORT int SSL_set1_host(SSL *ssl, const char *hostname);
2765 
2766 // SSL_set_hostflags calls |X509_VERIFY_PARAM_set_hostflags| on the
2767 // |X509_VERIFY_PARAM| associated with this |SSL*|. |flags| should be some
2768 // combination of the |X509_CHECK_*| constants.
2769 OPENSSL_EXPORT void SSL_set_hostflags(SSL *ssl, unsigned flags);
2770 
2771 // SSL_CTX_set_verify_depth sets the maximum depth of a certificate chain
2772 // accepted in verification. This count excludes both the target certificate and
2773 // the trust anchor (root certificate).
2774 OPENSSL_EXPORT void SSL_CTX_set_verify_depth(SSL_CTX *ctx, int depth);
2775 
2776 // SSL_set_verify_depth sets the maximum depth of a certificate chain accepted
2777 // in verification. This count excludes both the target certificate and the
2778 // trust anchor (root certificate).
2779 OPENSSL_EXPORT void SSL_set_verify_depth(SSL *ssl, int depth);
2780 
2781 // SSL_CTX_get_verify_depth returns the maximum depth of a certificate accepted
2782 // in verification.
2783 OPENSSL_EXPORT int SSL_CTX_get_verify_depth(const SSL_CTX *ctx);
2784 
2785 // SSL_get_verify_depth returns the maximum depth of a certificate accepted in
2786 // verification.
2787 OPENSSL_EXPORT int SSL_get_verify_depth(const SSL *ssl);
2788 
2789 // SSL_CTX_set1_param sets verification parameters from |param|. It returns one
2790 // on success and zero on failure. The caller retains ownership of |param|.
2791 OPENSSL_EXPORT int SSL_CTX_set1_param(SSL_CTX *ctx,
2792                                       const X509_VERIFY_PARAM *param);
2793 
2794 // SSL_set1_param sets verification parameters from |param|. It returns one on
2795 // success and zero on failure. The caller retains ownership of |param|.
2796 OPENSSL_EXPORT int SSL_set1_param(SSL *ssl,
2797                                   const X509_VERIFY_PARAM *param);
2798 
2799 // SSL_CTX_get0_param returns |ctx|'s |X509_VERIFY_PARAM| for certificate
2800 // verification. The caller must not release the returned pointer but may call
2801 // functions on it to configure it.
2802 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_CTX_get0_param(SSL_CTX *ctx);
2803 
2804 // SSL_get0_param returns |ssl|'s |X509_VERIFY_PARAM| for certificate
2805 // verification. The caller must not release the returned pointer but may call
2806 // functions on it to configure it.
2807 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_get0_param(SSL *ssl);
2808 
2809 // SSL_CTX_set_purpose sets |ctx|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
2810 // |purpose|. It returns one on success and zero on error.
2811 OPENSSL_EXPORT int SSL_CTX_set_purpose(SSL_CTX *ctx, int purpose);
2812 
2813 // SSL_set_purpose sets |ssl|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
2814 // |purpose|. It returns one on success and zero on error.
2815 OPENSSL_EXPORT int SSL_set_purpose(SSL *ssl, int purpose);
2816 
2817 // SSL_CTX_set_trust sets |ctx|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
2818 // |trust|. It returns one on success and zero on error.
2819 OPENSSL_EXPORT int SSL_CTX_set_trust(SSL_CTX *ctx, int trust);
2820 
2821 // SSL_set_trust sets |ssl|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
2822 // |trust|. It returns one on success and zero on error.
2823 OPENSSL_EXPORT int SSL_set_trust(SSL *ssl, int trust);
2824 
2825 // SSL_CTX_set_cert_store sets |ctx|'s certificate store to |store|. It takes
2826 // ownership of |store|. The store is used for certificate verification.
2827 //
2828 // The store is also used for the auto-chaining feature, but this is deprecated.
2829 // See also |SSL_MODE_NO_AUTO_CHAIN|.
2830 OPENSSL_EXPORT void SSL_CTX_set_cert_store(SSL_CTX *ctx, X509_STORE *store);
2831 
2832 // SSL_CTX_get_cert_store returns |ctx|'s certificate store.
2833 OPENSSL_EXPORT X509_STORE *SSL_CTX_get_cert_store(const SSL_CTX *ctx);
2834 
2835 // SSL_CTX_set_default_verify_paths calls |X509_STORE_set_default_paths| on
2836 // |ctx|'s store. See that function for details.
2837 //
2838 // Using this function is not recommended. In OpenSSL, these defaults are
2839 // determined by OpenSSL's install prefix. There is no corresponding concept for
2840 // BoringSSL. Future versions of BoringSSL may change or remove this
2841 // functionality.
2842 OPENSSL_EXPORT int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx);
2843 
2844 // SSL_CTX_load_verify_locations calls |X509_STORE_load_locations| on |ctx|'s
2845 // store. See that function for details.
2846 OPENSSL_EXPORT int SSL_CTX_load_verify_locations(SSL_CTX *ctx,
2847                                                  const char *ca_file,
2848                                                  const char *ca_dir);
2849 
2850 // SSL_get_verify_result returns the result of certificate verification. It is
2851 // either |X509_V_OK| or a |X509_V_ERR_*| value.
2852 OPENSSL_EXPORT long SSL_get_verify_result(const SSL *ssl);
2853 
2854 // SSL_alert_from_verify_result returns the SSL alert code, such as
2855 // |SSL_AD_CERTIFICATE_EXPIRED|, that corresponds to an |X509_V_ERR_*| value.
2856 // The return value is always an alert, even when |result| is |X509_V_OK|.
2857 OPENSSL_EXPORT int SSL_alert_from_verify_result(long result);
2858 
2859 // SSL_get_ex_data_X509_STORE_CTX_idx returns the ex_data index used to look up
2860 // the |SSL| associated with an |X509_STORE_CTX| in the verify callback.
2861 OPENSSL_EXPORT int SSL_get_ex_data_X509_STORE_CTX_idx(void);
2862 
2863 // SSL_CTX_set_cert_verify_callback sets a custom callback to be called on
2864 // certificate verification rather than |X509_verify_cert|. |store_ctx| contains
2865 // the verification parameters. The callback should return one on success and
2866 // zero on fatal error. It may use |X509_STORE_CTX_set_error| to set a
2867 // verification result.
2868 //
2869 // The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| to recover the
2870 // |SSL| object from |store_ctx|.
2871 OPENSSL_EXPORT void SSL_CTX_set_cert_verify_callback(
2872     SSL_CTX *ctx, int (*callback)(X509_STORE_CTX *store_ctx, void *arg),
2873     void *arg);
2874 
2875 // SSL_enable_signed_cert_timestamps causes |ssl| (which must be the client end
2876 // of a connection) to request SCTs from the server. See
2877 // https://tools.ietf.org/html/rfc6962.
2878 //
2879 // Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
2880 // handshake.
2881 OPENSSL_EXPORT void SSL_enable_signed_cert_timestamps(SSL *ssl);
2882 
2883 // SSL_CTX_enable_signed_cert_timestamps enables SCT requests on all client SSL
2884 // objects created from |ctx|.
2885 //
2886 // Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
2887 // handshake.
2888 OPENSSL_EXPORT void SSL_CTX_enable_signed_cert_timestamps(SSL_CTX *ctx);
2889 
2890 // SSL_enable_ocsp_stapling causes |ssl| (which must be the client end of a
2891 // connection) to request a stapled OCSP response from the server.
2892 //
2893 // Call |SSL_get0_ocsp_response| to recover the OCSP response after the
2894 // handshake.
2895 OPENSSL_EXPORT void SSL_enable_ocsp_stapling(SSL *ssl);
2896 
2897 // SSL_CTX_enable_ocsp_stapling enables OCSP stapling on all client SSL objects
2898 // created from |ctx|.
2899 //
2900 // Call |SSL_get0_ocsp_response| to recover the OCSP response after the
2901 // handshake.
2902 OPENSSL_EXPORT void SSL_CTX_enable_ocsp_stapling(SSL_CTX *ctx);
2903 
2904 // SSL_CTX_set0_verify_cert_store sets an |X509_STORE| that will be used
2905 // exclusively for certificate verification and returns one. Ownership of
2906 // |store| is transferred to the |SSL_CTX|.
2907 OPENSSL_EXPORT int SSL_CTX_set0_verify_cert_store(SSL_CTX *ctx,
2908                                                   X509_STORE *store);
2909 
2910 // SSL_CTX_set1_verify_cert_store sets an |X509_STORE| that will be used
2911 // exclusively for certificate verification and returns one. An additional
2912 // reference to |store| will be taken.
2913 OPENSSL_EXPORT int SSL_CTX_set1_verify_cert_store(SSL_CTX *ctx,
2914                                                   X509_STORE *store);
2915 
2916 // SSL_set0_verify_cert_store sets an |X509_STORE| that will be used
2917 // exclusively for certificate verification and returns one. Ownership of
2918 // |store| is transferred to the |SSL|.
2919 OPENSSL_EXPORT int SSL_set0_verify_cert_store(SSL *ssl, X509_STORE *store);
2920 
2921 // SSL_set1_verify_cert_store sets an |X509_STORE| that will be used
2922 // exclusively for certificate verification and returns one. An additional
2923 // reference to |store| will be taken.
2924 OPENSSL_EXPORT int SSL_set1_verify_cert_store(SSL *ssl, X509_STORE *store);
2925 
2926 // SSL_CTX_set_verify_algorithm_prefs configures |ctx| to use |prefs| as the
2927 // preference list when verifying signatures from the peer's long-term key. It
2928 // returns one on zero on error. |prefs| should not include the internal-only
2929 // value |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
2930 OPENSSL_EXPORT int SSL_CTX_set_verify_algorithm_prefs(SSL_CTX *ctx,
2931                                                       const uint16_t *prefs,
2932                                                       size_t num_prefs);
2933 
2934 // SSL_set_verify_algorithm_prefs configures |ssl| to use |prefs| as the
2935 // preference list when verifying signatures from the peer's long-term key. It
2936 // returns one on zero on error. |prefs| should not include the internal-only
2937 // value |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
2938 OPENSSL_EXPORT int SSL_set_verify_algorithm_prefs(SSL *ssl,
2939                                                   const uint16_t *prefs,
2940                                                   size_t num_prefs);
2941 
2942 
2943 // Client certificate CA list.
2944 //
2945 // When requesting a client certificate, a server may advertise a list of
2946 // certificate authorities which are accepted. These functions may be used to
2947 // configure this list.
2948 
2949 // SSL_set_client_CA_list sets |ssl|'s client certificate CA list to
2950 // |name_list|. It takes ownership of |name_list|.
2951 OPENSSL_EXPORT void SSL_set_client_CA_list(SSL *ssl,
2952                                            STACK_OF(X509_NAME) *name_list);
2953 
2954 // SSL_CTX_set_client_CA_list sets |ctx|'s client certificate CA list to
2955 // |name_list|. It takes ownership of |name_list|.
2956 OPENSSL_EXPORT void SSL_CTX_set_client_CA_list(SSL_CTX *ctx,
2957                                                STACK_OF(X509_NAME) *name_list);
2958 
2959 // SSL_set0_client_CAs sets |ssl|'s client certificate CA list to |name_list|,
2960 // which should contain DER-encoded distinguished names (RFC 5280). It takes
2961 // ownership of |name_list|.
2962 OPENSSL_EXPORT void SSL_set0_client_CAs(SSL *ssl,
2963                                         STACK_OF(CRYPTO_BUFFER) *name_list);
2964 
2965 // SSL_CTX_set0_client_CAs sets |ctx|'s client certificate CA list to
2966 // |name_list|, which should contain DER-encoded distinguished names (RFC 5280).
2967 // It takes ownership of |name_list|.
2968 OPENSSL_EXPORT void SSL_CTX_set0_client_CAs(SSL_CTX *ctx,
2969                                             STACK_OF(CRYPTO_BUFFER) *name_list);
2970 
2971 // SSL_get_client_CA_list returns |ssl|'s client certificate CA list. If |ssl|
2972 // has not been configured as a client, this is the list configured by
2973 // |SSL_CTX_set_client_CA_list|.
2974 //
2975 // If configured as a client, it returns the client certificate CA list sent by
2976 // the server. In this mode, the behavior is undefined except during the
2977 // callbacks set by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or
2978 // when the handshake is paused because of them.
2979 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_get_client_CA_list(const SSL *ssl);
2980 
2981 // SSL_get0_server_requested_CAs returns the CAs sent by a server to guide a
2982 // client in certificate selection. They are a series of DER-encoded X.509
2983 // names. This function may only be called during a callback set by
2984 // |SSL_CTX_set_cert_cb| or when the handshake is paused because of it.
2985 //
2986 // The returned stack is owned by |ssl|, as are its contents. It should not be
2987 // used past the point where the handshake is restarted after the callback.
2988 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER) *
2989     SSL_get0_server_requested_CAs(const SSL *ssl);
2990 
2991 // SSL_CTX_get_client_CA_list returns |ctx|'s client certificate CA list.
2992 OPENSSL_EXPORT STACK_OF(X509_NAME) *
2993     SSL_CTX_get_client_CA_list(const SSL_CTX *ctx);
2994 
2995 // SSL_add_client_CA appends |x509|'s subject to the client certificate CA list.
2996 // It returns one on success or zero on error. The caller retains ownership of
2997 // |x509|.
2998 OPENSSL_EXPORT int SSL_add_client_CA(SSL *ssl, X509 *x509);
2999 
3000 // SSL_CTX_add_client_CA appends |x509|'s subject to the client certificate CA
3001 // list. It returns one on success or zero on error. The caller retains
3002 // ownership of |x509|.
3003 OPENSSL_EXPORT int SSL_CTX_add_client_CA(SSL_CTX *ctx, X509 *x509);
3004 
3005 // SSL_load_client_CA_file opens |file| and reads PEM-encoded certificates from
3006 // it. It returns a newly-allocated stack of the certificate subjects or NULL
3007 // on error. Duplicates in |file| are ignored.
3008 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_load_client_CA_file(const char *file);
3009 
3010 // SSL_dup_CA_list makes a deep copy of |list|. It returns the new list on
3011 // success or NULL on allocation error.
3012 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_dup_CA_list(STACK_OF(X509_NAME) *list);
3013 
3014 // SSL_add_file_cert_subjects_to_stack behaves like |SSL_load_client_CA_file|
3015 // but appends the result to |out|. It returns one on success or zero on
3016 // error.
3017 OPENSSL_EXPORT int SSL_add_file_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
3018                                                        const char *file);
3019 
3020 // SSL_add_bio_cert_subjects_to_stack behaves like
3021 // |SSL_add_file_cert_subjects_to_stack| but reads from |bio|.
3022 OPENSSL_EXPORT int SSL_add_bio_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
3023                                                       BIO *bio);
3024 
3025 
3026 // Server name indication.
3027 //
3028 // The server_name extension (RFC 3546) allows the client to advertise the name
3029 // of the server it is connecting to. This is used in virtual hosting
3030 // deployments to select one of a several certificates on a single IP. Only the
3031 // host_name name type is supported.
3032 
3033 #define TLSEXT_NAMETYPE_host_name 0
3034 
3035 // SSL_set_tlsext_host_name, for a client, configures |ssl| to advertise |name|
3036 // in the server_name extension. It returns one on success and zero on error.
3037 OPENSSL_EXPORT int SSL_set_tlsext_host_name(SSL *ssl, const char *name);
3038 
3039 // SSL_get_servername, for a server, returns the hostname supplied by the
3040 // client or NULL if there was none. The |type| argument must be
3041 // |TLSEXT_NAMETYPE_host_name|.
3042 OPENSSL_EXPORT const char *SSL_get_servername(const SSL *ssl, const int type);
3043 
3044 // SSL_get_servername_type, for a server, returns |TLSEXT_NAMETYPE_host_name|
3045 // if the client sent a hostname and -1 otherwise.
3046 OPENSSL_EXPORT int SSL_get_servername_type(const SSL *ssl);
3047 
3048 // SSL_CTX_set_tlsext_servername_callback configures |callback| to be called on
3049 // the server after ClientHello extensions have been parsed and returns one.
3050 // The callback may use |SSL_get_servername| to examine the server_name
3051 // extension and returns a |SSL_TLSEXT_ERR_*| value. The value of |arg| may be
3052 // set by calling |SSL_CTX_set_tlsext_servername_arg|.
3053 //
3054 // If the callback returns |SSL_TLSEXT_ERR_NOACK|, the server_name extension is
3055 // not acknowledged in the ServerHello. If the return value is
3056 // |SSL_TLSEXT_ERR_ALERT_FATAL|, then |*out_alert| is the alert to send,
3057 // defaulting to |SSL_AD_UNRECOGNIZED_NAME|. |SSL_TLSEXT_ERR_ALERT_WARNING| is
3058 // ignored and treated as |SSL_TLSEXT_ERR_OK|.
3059 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_callback(
3060     SSL_CTX *ctx, int (*callback)(SSL *ssl, int *out_alert, void *arg));
3061 
3062 // SSL_CTX_set_tlsext_servername_arg sets the argument to the servername
3063 // callback and returns one. See |SSL_CTX_set_tlsext_servername_callback|.
3064 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);
3065 
3066 // SSL_TLSEXT_ERR_* are values returned by some extension-related callbacks.
3067 #define SSL_TLSEXT_ERR_OK 0
3068 #define SSL_TLSEXT_ERR_ALERT_WARNING 1
3069 #define SSL_TLSEXT_ERR_ALERT_FATAL 2
3070 #define SSL_TLSEXT_ERR_NOACK 3
3071 
3072 // SSL_set_SSL_CTX changes |ssl|'s |SSL_CTX|. |ssl| will use the
3073 // certificate-related settings from |ctx|, and |SSL_get_SSL_CTX| will report
3074 // |ctx|. This function may be used during the callbacks registered by
3075 // |SSL_CTX_set_select_certificate_cb|,
3076 // |SSL_CTX_set_tlsext_servername_callback|, and |SSL_CTX_set_cert_cb| or when
3077 // the handshake is paused from them. It is typically used to switch
3078 // certificates based on SNI.
3079 //
3080 // Note the session cache and related settings will continue to use the initial
3081 // |SSL_CTX|. Callers should use |SSL_CTX_set_session_id_context| to partition
3082 // the session cache between different domains.
3083 //
3084 // TODO(davidben): Should other settings change after this call?
3085 OPENSSL_EXPORT SSL_CTX *SSL_set_SSL_CTX(SSL *ssl, SSL_CTX *ctx);
3086 
3087 
3088 // Application-layer protocol negotiation.
3089 //
3090 // The ALPN extension (RFC 7301) allows negotiating different application-layer
3091 // protocols over a single port. This is used, for example, to negotiate
3092 // HTTP/2.
3093 
3094 // SSL_CTX_set_alpn_protos sets the client ALPN protocol list on |ctx| to
3095 // |protos|. |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
3096 // length-prefixed strings), or the empty string to disable ALPN. It returns
3097 // zero on success and one on failure. Configuring a non-empty string enables
3098 // ALPN on a client.
3099 //
3100 // WARNING: this function is dangerous because it breaks the usual return value
3101 // convention.
3102 OPENSSL_EXPORT int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
3103                                            size_t protos_len);
3104 
3105 // SSL_set_alpn_protos sets the client ALPN protocol list on |ssl| to |protos|.
3106 // |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
3107 // length-prefixed strings), or the empty string to disable ALPN. It returns
3108 // zero on success and one on failure. Configuring a non-empty string enables
3109 // ALPN on a client.
3110 //
3111 // WARNING: this function is dangerous because it breaks the usual return value
3112 // convention.
3113 OPENSSL_EXPORT int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos,
3114                                        size_t protos_len);
3115 
3116 // SSL_CTX_set_alpn_select_cb sets a callback function on |ctx| that is called
3117 // during ClientHello processing in order to select an ALPN protocol from the
3118 // client's list of offered protocols.
3119 //
3120 // The callback is passed a wire-format (i.e. a series of non-empty, 8-bit
3121 // length-prefixed strings) ALPN protocol list in |in|. To select a protocol,
3122 // the callback should set |*out| and |*out_len| to the selected protocol and
3123 // return |SSL_TLSEXT_ERR_OK| on success. It does not pass ownership of the
3124 // buffer, so |*out| should point to a static string, a buffer that outlives the
3125 // callback call, or the corresponding entry in |in|.
3126 //
3127 // If the server supports ALPN, but there are no protocols in common, the
3128 // callback should return |SSL_TLSEXT_ERR_ALERT_FATAL| to abort the connection
3129 // with a no_application_protocol alert.
3130 //
3131 // If the server does not support ALPN, it can return |SSL_TLSEXT_ERR_NOACK| to
3132 // continue the handshake without negotiating a protocol. This may be useful if
3133 // multiple server configurations share an |SSL_CTX|, only some of which have
3134 // ALPN protocols configured.
3135 //
3136 // |SSL_TLSEXT_ERR_ALERT_WARNING| is ignored and will be treated as
3137 // |SSL_TLSEXT_ERR_NOACK|.
3138 //
3139 // The callback will only be called if the client supports ALPN. Callers that
3140 // wish to require ALPN for all clients must check |SSL_get0_alpn_selected|
3141 // after the handshake. In QUIC connections, this is done automatically.
3142 //
3143 // The cipher suite is selected before negotiating ALPN. The callback may use
3144 // |SSL_get_pending_cipher| to query the cipher suite. This may be used to
3145 // implement HTTP/2's cipher suite constraints.
3146 OPENSSL_EXPORT void SSL_CTX_set_alpn_select_cb(
3147     SSL_CTX *ctx, int (*cb)(SSL *ssl, const uint8_t **out, uint8_t *out_len,
3148                             const uint8_t *in, unsigned in_len, void *arg),
3149     void *arg);
3150 
3151 // SSL_get0_alpn_selected gets the selected ALPN protocol (if any) from |ssl|.
3152 // On return it sets |*out_data| to point to |*out_len| bytes of protocol name
3153 // (not including the leading length-prefix byte). If the server didn't respond
3154 // with a negotiated protocol then |*out_len| will be zero.
3155 OPENSSL_EXPORT void SSL_get0_alpn_selected(const SSL *ssl,
3156                                            const uint8_t **out_data,
3157                                            unsigned *out_len);
3158 
3159 // SSL_CTX_set_allow_unknown_alpn_protos configures client connections on |ctx|
3160 // to allow unknown ALPN protocols from the server. Otherwise, by default, the
3161 // client will require that the protocol be advertised in
3162 // |SSL_CTX_set_alpn_protos|.
3163 OPENSSL_EXPORT void SSL_CTX_set_allow_unknown_alpn_protos(SSL_CTX *ctx,
3164                                                           int enabled);
3165 
3166 
3167 // Application-layer protocol settings
3168 //
3169 // The ALPS extension (draft-vvv-tls-alps) allows exchanging application-layer
3170 // settings in the TLS handshake for applications negotiated with ALPN. Note
3171 // that, when ALPS is negotiated, the client and server each advertise their own
3172 // settings, so there are functions to both configure setting to send and query
3173 // received settings.
3174 
3175 // SSL_add_application_settings configures |ssl| to enable ALPS with ALPN
3176 // protocol |proto|, sending an ALPS value of |settings|. It returns one on
3177 // success and zero on error. If |proto| is negotiated via ALPN and the peer
3178 // supports ALPS, |settings| will be sent to the peer. The peer's ALPS value can
3179 // be retrieved with |SSL_get0_peer_application_settings|.
3180 //
3181 // On the client, this function should be called before the handshake, once for
3182 // each supported ALPN protocol which uses ALPS. |proto| must be included in the
3183 // client's ALPN configuration (see |SSL_CTX_set_alpn_protos| and
3184 // |SSL_set_alpn_protos|). On the server, ALPS can be preconfigured for each
3185 // protocol as in the client, or configuration can be deferred to the ALPN
3186 // callback (see |SSL_CTX_set_alpn_select_cb|), in which case only the selected
3187 // protocol needs to be configured.
3188 //
3189 // ALPS can be independently configured from 0-RTT, however changes in protocol
3190 // settings will fallback to 1-RTT to negotiate the new value, so it is
3191 // recommended for |settings| to be relatively stable.
3192 OPENSSL_EXPORT int SSL_add_application_settings(SSL *ssl, const uint8_t *proto,
3193                                                 size_t proto_len,
3194                                                 const uint8_t *settings,
3195                                                 size_t settings_len);
3196 
3197 // SSL_get0_peer_application_settings sets |*out_data| and |*out_len| to a
3198 // buffer containing the peer's ALPS value, or the empty string if ALPS was not
3199 // negotiated. Note an empty string could also indicate the peer sent an empty
3200 // settings value. Use |SSL_has_application_settings| to check if ALPS was
3201 // negotiated. The output buffer is owned by |ssl| and is valid until the next
3202 // time |ssl| is modified.
3203 OPENSSL_EXPORT void SSL_get0_peer_application_settings(const SSL *ssl,
3204                                                        const uint8_t **out_data,
3205                                                        size_t *out_len);
3206 
3207 // SSL_has_application_settings returns one if ALPS was negotiated on this
3208 // connection and zero otherwise.
3209 OPENSSL_EXPORT int SSL_has_application_settings(const SSL *ssl);
3210 
3211 // SSL_set_alps_use_new_codepoint configures whether to use the new ALPS
3212 // codepoint. By default, the old codepoint is used.
3213 OPENSSL_EXPORT void SSL_set_alps_use_new_codepoint(SSL *ssl, int use_new);
3214 
3215 
3216 // Certificate compression.
3217 //
3218 // Certificates in TLS 1.3 can be compressed (RFC 8879). BoringSSL supports this
3219 // as both a client and a server, but does not link against any specific
3220 // compression libraries in order to keep dependencies to a minimum. Instead,
3221 // hooks for compression and decompression can be installed in an |SSL_CTX| to
3222 // enable support.
3223 
3224 // ssl_cert_compression_func_t is a pointer to a function that performs
3225 // compression. It must write the compressed representation of |in| to |out|,
3226 // returning one on success and zero on error. The results of compressing
3227 // certificates are not cached internally. Implementations may wish to implement
3228 // their own cache if they expect it to be useful given the certificates that
3229 // they serve.
3230 typedef int (*ssl_cert_compression_func_t)(SSL *ssl, CBB *out,
3231                                            const uint8_t *in, size_t in_len);
3232 
3233 // ssl_cert_decompression_func_t is a pointer to a function that performs
3234 // decompression. The compressed data from the peer is passed as |in| and the
3235 // decompressed result must be exactly |uncompressed_len| bytes long. It returns
3236 // one on success, in which case |*out| must be set to the result of
3237 // decompressing |in|, or zero on error. Setting |*out| transfers ownership,
3238 // i.e. |CRYPTO_BUFFER_free| will be called on |*out| at some point in the
3239 // future. The results of decompressions are not cached internally.
3240 // Implementations may wish to implement their own cache if they expect it to be
3241 // useful.
3242 typedef int (*ssl_cert_decompression_func_t)(SSL *ssl, CRYPTO_BUFFER **out,
3243                                              size_t uncompressed_len,
3244                                              const uint8_t *in, size_t in_len);
3245 
3246 // SSL_CTX_add_cert_compression_alg registers a certificate compression
3247 // algorithm on |ctx| with ID |alg_id|. (The value of |alg_id| should be an IANA
3248 // assigned value and each can only be registered once.)
3249 //
3250 // One of the function pointers may be NULL to avoid having to implement both
3251 // sides of a compression algorithm if you're only going to use it in one
3252 // direction. In this case, the unimplemented direction acts like it was never
3253 // configured.
3254 //
3255 // For a server, algorithms are registered in preference order with the most
3256 // preferable first. It returns one on success or zero on error.
3257 OPENSSL_EXPORT int SSL_CTX_add_cert_compression_alg(
3258     SSL_CTX *ctx, uint16_t alg_id, ssl_cert_compression_func_t compress,
3259     ssl_cert_decompression_func_t decompress);
3260 
3261 
3262 // Next protocol negotiation.
3263 //
3264 // The NPN extension (draft-agl-tls-nextprotoneg-03) is the predecessor to ALPN
3265 // and deprecated in favor of it.
3266 
3267 // SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a
3268 // TLS server needs a list of supported protocols for Next Protocol
3269 // Negotiation. The returned list must be in wire format. The list is returned
3270 // by setting |*out| to point to it and |*out_len| to its length. This memory
3271 // will not be modified, but one should assume that |ssl| keeps a reference to
3272 // it.
3273 //
3274 // The callback should return |SSL_TLSEXT_ERR_OK| if it wishes to advertise.
3275 // Otherwise, no such extension will be included in the ServerHello.
3276 OPENSSL_EXPORT void SSL_CTX_set_next_protos_advertised_cb(
3277     SSL_CTX *ctx,
3278     int (*cb)(SSL *ssl, const uint8_t **out, unsigned *out_len, void *arg),
3279     void *arg);
3280 
3281 // SSL_CTX_set_next_proto_select_cb sets a callback that is called when a client
3282 // needs to select a protocol from the server's provided list. |*out| must be
3283 // set to point to the selected protocol (which may be within |in|). The length
3284 // of the protocol name must be written into |*out_len|. The server's advertised
3285 // protocols are provided in |in| and |in_len|. The callback can assume that
3286 // |in| is syntactically valid.
3287 //
3288 // The client must select a protocol. It is fatal to the connection if this
3289 // callback returns a value other than |SSL_TLSEXT_ERR_OK|.
3290 //
3291 // Configuring this callback enables NPN on a client.
3292 OPENSSL_EXPORT void SSL_CTX_set_next_proto_select_cb(
3293     SSL_CTX *ctx, int (*cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
3294                             const uint8_t *in, unsigned in_len, void *arg),
3295     void *arg);
3296 
3297 // SSL_get0_next_proto_negotiated sets |*out_data| and |*out_len| to point to
3298 // the client's requested protocol for this connection. If the client didn't
3299 // request any protocol, then |*out_data| is set to NULL.
3300 //
3301 // Note that the client can request any protocol it chooses. The value returned
3302 // from this function need not be a member of the list of supported protocols
3303 // provided by the server.
3304 OPENSSL_EXPORT void SSL_get0_next_proto_negotiated(const SSL *ssl,
3305                                                    const uint8_t **out_data,
3306                                                    unsigned *out_len);
3307 
3308 // SSL_select_next_proto implements the standard protocol selection. It is
3309 // expected that this function is called from the callback set by
3310 // |SSL_CTX_set_next_proto_select_cb|.
3311 //
3312 // |peer| and |supported| must be vectors of 8-bit, length-prefixed byte strings
3313 // containing the peer and locally-configured protocols, respectively. The
3314 // length byte itself is not included in the length. A byte string of length 0
3315 // is invalid. No byte string may be truncated. |supported| is assumed to be
3316 // non-empty.
3317 //
3318 // This function finds the first protocol in |peer| which is also in
3319 // |supported|. If one was found, it sets |*out| and |*out_len| to point to it
3320 // and returns |OPENSSL_NPN_NEGOTIATED|. Otherwise, it returns
3321 // |OPENSSL_NPN_NO_OVERLAP| and sets |*out| and |*out_len| to the first
3322 // supported protocol.
3323 OPENSSL_EXPORT int SSL_select_next_proto(uint8_t **out, uint8_t *out_len,
3324                                          const uint8_t *peer, unsigned peer_len,
3325                                          const uint8_t *supported,
3326                                          unsigned supported_len);
3327 
3328 #define OPENSSL_NPN_UNSUPPORTED 0
3329 #define OPENSSL_NPN_NEGOTIATED 1
3330 #define OPENSSL_NPN_NO_OVERLAP 2
3331 
3332 
3333 // Channel ID.
3334 //
3335 // See draft-balfanz-tls-channelid-01. This is an old, experimental mechanism
3336 // and should not be used in new code.
3337 
3338 // SSL_CTX_set_tls_channel_id_enabled configures whether connections associated
3339 // with |ctx| should enable Channel ID as a server.
3340 OPENSSL_EXPORT void SSL_CTX_set_tls_channel_id_enabled(SSL_CTX *ctx,
3341                                                        int enabled);
3342 
3343 // SSL_set_tls_channel_id_enabled configures whether |ssl| should enable Channel
3344 // ID as a server.
3345 OPENSSL_EXPORT void SSL_set_tls_channel_id_enabled(SSL *ssl, int enabled);
3346 
3347 // SSL_CTX_set1_tls_channel_id configures a TLS client to send a TLS Channel ID
3348 // to compatible servers. |private_key| must be a P-256 EC key. It returns one
3349 // on success and zero on error.
3350 OPENSSL_EXPORT int SSL_CTX_set1_tls_channel_id(SSL_CTX *ctx,
3351                                                EVP_PKEY *private_key);
3352 
3353 // SSL_set1_tls_channel_id configures a TLS client to send a TLS Channel ID to
3354 // compatible servers. |private_key| must be a P-256 EC key. It returns one on
3355 // success and zero on error.
3356 OPENSSL_EXPORT int SSL_set1_tls_channel_id(SSL *ssl, EVP_PKEY *private_key);
3357 
3358 // SSL_get_tls_channel_id gets the client's TLS Channel ID from a server |SSL|
3359 // and copies up to the first |max_out| bytes into |out|. The Channel ID
3360 // consists of the client's P-256 public key as an (x,y) pair where each is a
3361 // 32-byte, big-endian field element. It returns 0 if the client didn't offer a
3362 // Channel ID and the length of the complete Channel ID otherwise. This function
3363 // always returns zero if |ssl| is a client.
3364 OPENSSL_EXPORT size_t SSL_get_tls_channel_id(SSL *ssl, uint8_t *out,
3365                                              size_t max_out);
3366 
3367 
3368 // DTLS-SRTP.
3369 //
3370 // See RFC 5764.
3371 
3372 // srtp_protection_profile_st (aka |SRTP_PROTECTION_PROFILE|) is an SRTP
3373 // profile for use with the use_srtp extension.
3374 struct srtp_protection_profile_st {
3375   const char *name;
3376   unsigned long id;
3377 } /* SRTP_PROTECTION_PROFILE */;
3378 
3379 DEFINE_CONST_STACK_OF(SRTP_PROTECTION_PROFILE)
3380 
3381 // SRTP_* define constants for SRTP profiles.
3382 #define SRTP_AES128_CM_SHA1_80 0x0001
3383 #define SRTP_AES128_CM_SHA1_32 0x0002
3384 #define SRTP_AES128_F8_SHA1_80 0x0003
3385 #define SRTP_AES128_F8_SHA1_32 0x0004
3386 #define SRTP_NULL_SHA1_80      0x0005
3387 #define SRTP_NULL_SHA1_32      0x0006
3388 #define SRTP_AEAD_AES_128_GCM  0x0007
3389 #define SRTP_AEAD_AES_256_GCM  0x0008
3390 
3391 // SSL_CTX_set_srtp_profiles enables SRTP for all SSL objects created from
3392 // |ctx|. |profile| contains a colon-separated list of profile names. It returns
3393 // one on success and zero on failure.
3394 OPENSSL_EXPORT int SSL_CTX_set_srtp_profiles(SSL_CTX *ctx,
3395                                              const char *profiles);
3396 
3397 // SSL_set_srtp_profiles enables SRTP for |ssl|.  |profile| contains a
3398 // colon-separated list of profile names. It returns one on success and zero on
3399 // failure.
3400 OPENSSL_EXPORT int SSL_set_srtp_profiles(SSL *ssl, const char *profiles);
3401 
3402 // SSL_get_srtp_profiles returns the SRTP profiles supported by |ssl|.
3403 OPENSSL_EXPORT const STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(
3404     const SSL *ssl);
3405 
3406 // SSL_get_selected_srtp_profile returns the selected SRTP profile, or NULL if
3407 // SRTP was not negotiated.
3408 OPENSSL_EXPORT const SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(
3409     SSL *ssl);
3410 
3411 
3412 // Pre-shared keys.
3413 //
3414 // Connections may be configured with PSK (Pre-Shared Key) cipher suites. These
3415 // authenticate using out-of-band pre-shared keys rather than certificates. See
3416 // RFC 4279.
3417 //
3418 // This implementation uses NUL-terminated C strings for identities and identity
3419 // hints, so values with a NUL character are not supported. (RFC 4279 does not
3420 // specify the format of an identity.)
3421 
3422 // PSK_MAX_IDENTITY_LEN is the maximum supported length of a PSK identity,
3423 // excluding the NUL terminator.
3424 #define PSK_MAX_IDENTITY_LEN 128
3425 
3426 // PSK_MAX_PSK_LEN is the maximum supported length of a pre-shared key.
3427 #define PSK_MAX_PSK_LEN 256
3428 
3429 // SSL_CTX_set_psk_client_callback sets the callback to be called when PSK is
3430 // negotiated on the client. This callback must be set to enable PSK cipher
3431 // suites on the client.
3432 //
3433 // The callback is passed the identity hint in |hint| or NULL if none was
3434 // provided. It should select a PSK identity and write the identity and the
3435 // corresponding PSK to |identity| and |psk|, respectively. The identity is
3436 // written as a NUL-terminated C string of length (excluding the NUL terminator)
3437 // at most |max_identity_len|. The PSK's length must be at most |max_psk_len|.
3438 // The callback returns the length of the PSK or 0 if no suitable identity was
3439 // found.
3440 OPENSSL_EXPORT void SSL_CTX_set_psk_client_callback(
3441     SSL_CTX *ctx, unsigned (*cb)(SSL *ssl, const char *hint, char *identity,
3442                                  unsigned max_identity_len, uint8_t *psk,
3443                                  unsigned max_psk_len));
3444 
3445 // SSL_set_psk_client_callback sets the callback to be called when PSK is
3446 // negotiated on the client. This callback must be set to enable PSK cipher
3447 // suites on the client. See also |SSL_CTX_set_psk_client_callback|.
3448 OPENSSL_EXPORT void SSL_set_psk_client_callback(
3449     SSL *ssl, unsigned (*cb)(SSL *ssl, const char *hint, char *identity,
3450                              unsigned max_identity_len, uint8_t *psk,
3451                              unsigned max_psk_len));
3452 
3453 // SSL_CTX_set_psk_server_callback sets the callback to be called when PSK is
3454 // negotiated on the server. This callback must be set to enable PSK cipher
3455 // suites on the server.
3456 //
3457 // The callback is passed the identity in |identity|. It should write a PSK of
3458 // length at most |max_psk_len| to |psk| and return the number of bytes written
3459 // or zero if the PSK identity is unknown.
3460 OPENSSL_EXPORT void SSL_CTX_set_psk_server_callback(
3461     SSL_CTX *ctx, unsigned (*cb)(SSL *ssl, const char *identity, uint8_t *psk,
3462                                  unsigned max_psk_len));
3463 
3464 // SSL_set_psk_server_callback sets the callback to be called when PSK is
3465 // negotiated on the server. This callback must be set to enable PSK cipher
3466 // suites on the server. See also |SSL_CTX_set_psk_server_callback|.
3467 OPENSSL_EXPORT void SSL_set_psk_server_callback(
3468     SSL *ssl, unsigned (*cb)(SSL *ssl, const char *identity, uint8_t *psk,
3469                              unsigned max_psk_len));
3470 
3471 // SSL_CTX_use_psk_identity_hint configures server connections to advertise an
3472 // identity hint of |identity_hint|. It returns one on success and zero on
3473 // error.
3474 OPENSSL_EXPORT int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx,
3475                                                  const char *identity_hint);
3476 
3477 // SSL_use_psk_identity_hint configures server connections to advertise an
3478 // identity hint of |identity_hint|. It returns one on success and zero on
3479 // error.
3480 OPENSSL_EXPORT int SSL_use_psk_identity_hint(SSL *ssl,
3481                                              const char *identity_hint);
3482 
3483 // SSL_get_psk_identity_hint returns the PSK identity hint advertised for |ssl|
3484 // or NULL if there is none.
3485 OPENSSL_EXPORT const char *SSL_get_psk_identity_hint(const SSL *ssl);
3486 
3487 // SSL_get_psk_identity, after the handshake completes, returns the PSK identity
3488 // that was negotiated by |ssl| or NULL if PSK was not used.
3489 OPENSSL_EXPORT const char *SSL_get_psk_identity(const SSL *ssl);
3490 
3491 
3492 // Delegated credentials.
3493 //
3494 // Delegated credentials (RFC 9345) allow a TLS 1.3 endpoint to use its
3495 // certificate to issue new credentials for authentication. Once issued,
3496 // credentials can't be revoked. In order to mitigate the damage in case the
3497 // credential secret key is compromised, the credential is only valid for a
3498 // short time (days, hours, or even minutes).
3499 //
3500 // Currently only the authenticating side, as a server, is implemented. To
3501 // authenticate with delegated credentials, construct an |SSL_CREDENTIAL| with
3502 // |SSL_CREDENTIAL_new_delegated| and add it to the credential list. See also
3503 // |SSL_CTX_add1_credential|. Callers may configure a mix of delegated
3504 // credentials and X.509 credentials on the same |SSL| or |SSL_CTX| to support a
3505 // range of clients.
3506 
3507 // SSL_CREDENTIAL_new_delegated returns a new, empty delegated credential, or
3508 // NULL on error. Callers should release the result with |SSL_CREDENTIAL_free|
3509 // when done.
3510 //
3511 // Callers should configure a delegated credential, certificate chain and
3512 // private key on the credential, along with other properties, then add it with
3513 // |SSL_CTX_add1_credential|.
3514 OPENSSL_EXPORT SSL_CREDENTIAL *SSL_CREDENTIAL_new_delegated(void);
3515 
3516 // SSL_CREDENTIAL_set1_delegated_credential sets |cred|'s delegated credentials
3517 // structure to |dc|. It returns one on success and zero on error, including if
3518 // |dc| is malformed. This should be a DelegatedCredential structure, signed by
3519 // the end-entity certificate, as described in RFC 9345.
3520 OPENSSL_EXPORT int SSL_CREDENTIAL_set1_delegated_credential(
3521     SSL_CREDENTIAL *cred, CRYPTO_BUFFER *dc);
3522 
3523 
3524 // QUIC integration.
3525 //
3526 // QUIC acts as an underlying transport for the TLS 1.3 handshake. The following
3527 // functions allow a QUIC implementation to serve as the underlying transport as
3528 // described in RFC 9001.
3529 //
3530 // When configured for QUIC, |SSL_do_handshake| will drive the handshake as
3531 // before, but it will not use the configured |BIO|. It will call functions on
3532 // |SSL_QUIC_METHOD| to configure secrets and send data. If data is needed from
3533 // the peer, it will return |SSL_ERROR_WANT_READ|. As the caller receives data
3534 // it can decrypt, it calls |SSL_provide_quic_data|. Subsequent
3535 // |SSL_do_handshake| calls will then consume that data and progress the
3536 // handshake. After the handshake is complete, the caller should continue to
3537 // call |SSL_provide_quic_data| for any post-handshake data, followed by
3538 // |SSL_process_quic_post_handshake| to process it. It is an error to call
3539 // |SSL_read| and |SSL_write| in QUIC.
3540 //
3541 // 0-RTT behaves similarly to |TLS_method|'s usual behavior. |SSL_do_handshake|
3542 // returns early as soon as the client (respectively, server) is allowed to send
3543 // 0-RTT (respectively, half-RTT) data. The caller should then call
3544 // |SSL_do_handshake| again to consume the remaining handshake messages and
3545 // confirm the handshake. As a client, |SSL_ERROR_EARLY_DATA_REJECTED| and
3546 // |SSL_reset_early_data_reject| behave as usual.
3547 //
3548 // See https://www.rfc-editor.org/rfc/rfc9001.html#section-4.1 for more details.
3549 //
3550 // To avoid DoS attacks, the QUIC implementation must limit the amount of data
3551 // being queued up. The implementation can call
3552 // |SSL_quic_max_handshake_flight_len| to get the maximum buffer length at each
3553 // encryption level.
3554 //
3555 // QUIC implementations must additionally configure transport parameters with
3556 // |SSL_set_quic_transport_params|. |SSL_get_peer_quic_transport_params| may be
3557 // used to query the value received from the peer. BoringSSL handles this
3558 // extension as an opaque byte string. The caller is responsible for serializing
3559 // and parsing them. See https://www.rfc-editor.org/rfc/rfc9000#section-7.4 for
3560 // details.
3561 //
3562 // QUIC additionally imposes restrictions on 0-RTT. In particular, the QUIC
3563 // transport layer requires that if a server accepts 0-RTT data, then the
3564 // transport parameters sent on the resumed connection must not lower any limits
3565 // compared to the transport parameters that the server sent on the connection
3566 // where the ticket for 0-RTT was issued. In effect, the server must remember
3567 // the transport parameters with the ticket. Application protocols running on
3568 // QUIC may impose similar restrictions, for example HTTP/3's restrictions on
3569 // SETTINGS frames.
3570 //
3571 // BoringSSL implements this check by doing a byte-for-byte comparison of an
3572 // opaque context passed in by the server. This context must be the same on the
3573 // connection where the ticket was issued and the connection where that ticket
3574 // is used for 0-RTT. If there is a mismatch, or the context was not set,
3575 // BoringSSL will reject early data (but not reject the resumption attempt).
3576 // This context is set via |SSL_set_quic_early_data_context| and should cover
3577 // both transport parameters and any application state.
3578 // |SSL_set_quic_early_data_context| must be called on the server with a
3579 // non-empty context if the server is to support 0-RTT in QUIC.
3580 //
3581 // BoringSSL does not perform any client-side checks on the transport
3582 // parameters received from a server that also accepted early data. It is up to
3583 // the caller to verify that the received transport parameters do not lower any
3584 // limits, and to close the QUIC connection if that is not the case. The same
3585 // holds for any application protocol state remembered for 0-RTT, e.g. HTTP/3
3586 // SETTINGS.
3587 
3588 // ssl_encryption_level_t represents a specific QUIC encryption level used to
3589 // transmit handshake messages.
3590 enum ssl_encryption_level_t BORINGSSL_ENUM_INT {
3591   ssl_encryption_initial = 0,
3592   ssl_encryption_early_data,
3593   ssl_encryption_handshake,
3594   ssl_encryption_application,
3595 };
3596 
3597 // ssl_quic_method_st (aka |SSL_QUIC_METHOD|) describes custom QUIC hooks.
3598 struct ssl_quic_method_st {
3599   // set_read_secret configures the read secret and cipher suite for the given
3600   // encryption level. It returns one on success and zero to terminate the
3601   // handshake with an error. It will be called at most once per encryption
3602   // level.
3603   //
3604   // BoringSSL will not release read keys before QUIC may use them. Once a level
3605   // has been initialized, QUIC may begin processing data from it. Handshake
3606   // data should be passed to |SSL_provide_quic_data| and application data (if
3607   // |level| is |ssl_encryption_early_data| or |ssl_encryption_application|) may
3608   // be processed according to the rules of the QUIC protocol.
3609   //
3610   // QUIC ACKs packets at the same encryption level they were received at,
3611   // except that client |ssl_encryption_early_data| (0-RTT) packets trigger
3612   // server |ssl_encryption_application| (1-RTT) ACKs. BoringSSL will always
3613   // install ACK-writing keys with |set_write_secret| before the packet-reading
3614   // keys with |set_read_secret|. This ensures the caller can always ACK any
3615   // packet it decrypts. Note this means the server installs 1-RTT write keys
3616   // before 0-RTT read keys.
3617   //
3618   // The converse is not true. An encryption level may be configured with write
3619   // secrets a roundtrip before the corresponding secrets for reading ACKs is
3620   // available.
3621   int (*set_read_secret)(SSL *ssl, enum ssl_encryption_level_t level,
3622                          const SSL_CIPHER *cipher, const uint8_t *secret,
3623                          size_t secret_len);
3624   // set_write_secret behaves like |set_read_secret| but configures the write
3625   // secret and cipher suite for the given encryption level. It will be called
3626   // at most once per encryption level.
3627   //
3628   // BoringSSL will not release write keys before QUIC may use them. If |level|
3629   // is |ssl_encryption_early_data| or |ssl_encryption_application|, QUIC may
3630   // begin sending application data at |level|. However, note that BoringSSL
3631   // configures server |ssl_encryption_application| write keys before the client
3632   // Finished. This allows QUIC to send half-RTT data, but the handshake is not
3633   // confirmed at this point and, if requesting client certificates, the client
3634   // is not yet authenticated.
3635   //
3636   // See |set_read_secret| for additional invariants between packets and their
3637   // ACKs.
3638   //
3639   // Note that, on 0-RTT reject, the |ssl_encryption_early_data| write secret
3640   // may use a different cipher suite from the other keys.
3641   int (*set_write_secret)(SSL *ssl, enum ssl_encryption_level_t level,
3642                           const SSL_CIPHER *cipher, const uint8_t *secret,
3643                           size_t secret_len);
3644   // add_handshake_data adds handshake data to the current flight at the given
3645   // encryption level. It returns one on success and zero on error.
3646   //
3647   // BoringSSL will pack data from a single encryption level together, but a
3648   // single handshake flight may include multiple encryption levels. Callers
3649   // should defer writing data to the network until |flush_flight| to better
3650   // pack QUIC packets into transport datagrams.
3651   //
3652   // If |level| is not |ssl_encryption_initial|, this function will not be
3653   // called before |level| is initialized with |set_write_secret|.
3654   int (*add_handshake_data)(SSL *ssl, enum ssl_encryption_level_t level,
3655                             const uint8_t *data, size_t len);
3656   // flush_flight is called when the current flight is complete and should be
3657   // written to the transport. Note a flight may contain data at several
3658   // encryption levels. It returns one on success and zero on error.
3659   int (*flush_flight)(SSL *ssl);
3660   // send_alert sends a fatal alert at the specified encryption level. It
3661   // returns one on success and zero on error.
3662   //
3663   // If |level| is not |ssl_encryption_initial|, this function will not be
3664   // called before |level| is initialized with |set_write_secret|.
3665   int (*send_alert)(SSL *ssl, enum ssl_encryption_level_t level, uint8_t alert);
3666 };
3667 
3668 // SSL_quic_max_handshake_flight_len returns returns the maximum number of bytes
3669 // that may be received at the given encryption level. This function should be
3670 // used to limit buffering in the QUIC implementation.
3671 //
3672 // See https://www.rfc-editor.org/rfc/rfc9000#section-7.5
3673 OPENSSL_EXPORT size_t SSL_quic_max_handshake_flight_len(
3674     const SSL *ssl, enum ssl_encryption_level_t level);
3675 
3676 // SSL_quic_read_level returns the current read encryption level.
3677 //
3678 // TODO(davidben): Is it still necessary to expose this function to callers?
3679 // QUICHE does not use it.
3680 OPENSSL_EXPORT enum ssl_encryption_level_t SSL_quic_read_level(const SSL *ssl);
3681 
3682 // SSL_quic_write_level returns the current write encryption level.
3683 //
3684 // TODO(davidben): Is it still necessary to expose this function to callers?
3685 // QUICHE does not use it.
3686 OPENSSL_EXPORT enum ssl_encryption_level_t SSL_quic_write_level(const SSL *ssl);
3687 
3688 // SSL_provide_quic_data provides data from QUIC at a particular encryption
3689 // level |level|. It returns one on success and zero on error. Note this
3690 // function will return zero if the handshake is not expecting data from |level|
3691 // at this time. The QUIC implementation should then close the connection with
3692 // an error.
3693 OPENSSL_EXPORT int SSL_provide_quic_data(SSL *ssl,
3694                                          enum ssl_encryption_level_t level,
3695                                          const uint8_t *data, size_t len);
3696 
3697 
3698 // SSL_process_quic_post_handshake processes any data that QUIC has provided
3699 // after the handshake has completed. This includes NewSessionTicket messages
3700 // sent by the server. It returns one on success and zero on error.
3701 OPENSSL_EXPORT int SSL_process_quic_post_handshake(SSL *ssl);
3702 
3703 // SSL_CTX_set_quic_method configures the QUIC hooks. This should only be
3704 // configured with a minimum version of TLS 1.3. |quic_method| must remain valid
3705 // for the lifetime of |ctx|. It returns one on success and zero on error.
3706 OPENSSL_EXPORT int SSL_CTX_set_quic_method(SSL_CTX *ctx,
3707                                            const SSL_QUIC_METHOD *quic_method);
3708 
3709 // SSL_set_quic_method configures the QUIC hooks. This should only be
3710 // configured with a minimum version of TLS 1.3. |quic_method| must remain valid
3711 // for the lifetime of |ssl|. It returns one on success and zero on error.
3712 OPENSSL_EXPORT int SSL_set_quic_method(SSL *ssl,
3713                                        const SSL_QUIC_METHOD *quic_method);
3714 
3715 // SSL_set_quic_transport_params configures |ssl| to send |params| (of length
3716 // |params_len|) in the quic_transport_parameters extension in either the
3717 // ClientHello or EncryptedExtensions handshake message. It is an error to set
3718 // transport parameters if |ssl| is not configured for QUIC. The buffer pointed
3719 // to by |params| only need be valid for the duration of the call to this
3720 // function. This function returns 1 on success and 0 on failure.
3721 OPENSSL_EXPORT int SSL_set_quic_transport_params(SSL *ssl,
3722                                                  const uint8_t *params,
3723                                                  size_t params_len);
3724 
3725 // SSL_get_peer_quic_transport_params provides the caller with the value of the
3726 // quic_transport_parameters extension sent by the peer. A pointer to the buffer
3727 // containing the TransportParameters will be put in |*out_params|, and its
3728 // length in |*params_len|. This buffer will be valid for the lifetime of the
3729 // |SSL|. If no params were received from the peer, |*out_params_len| will be 0.
3730 OPENSSL_EXPORT void SSL_get_peer_quic_transport_params(
3731     const SSL *ssl, const uint8_t **out_params, size_t *out_params_len);
3732 
3733 // SSL_set_quic_use_legacy_codepoint configures whether to use the legacy QUIC
3734 // extension codepoint 0xffa5 as opposed to the official value 57. Call with
3735 // |use_legacy| set to 1 to use 0xffa5 and call with 0 to use 57. By default,
3736 // the standard code point is used.
3737 OPENSSL_EXPORT void SSL_set_quic_use_legacy_codepoint(SSL *ssl, int use_legacy);
3738 
3739 // SSL_set_quic_early_data_context configures a context string in QUIC servers
3740 // for accepting early data. If a resumption connection offers early data, the
3741 // server will check if the value matches that of the connection which minted
3742 // the ticket. If not, resumption still succeeds but early data is rejected.
3743 // This should include all QUIC Transport Parameters except ones specified that
3744 // the client MUST NOT remember. This should also include any application
3745 // protocol-specific state. For HTTP/3, this should be the serialized server
3746 // SETTINGS frame and the QUIC Transport Parameters (except the stateless reset
3747 // token).
3748 //
3749 // This function may be called before |SSL_do_handshake| or during server
3750 // certificate selection. It returns 1 on success and 0 on failure.
3751 OPENSSL_EXPORT int SSL_set_quic_early_data_context(SSL *ssl,
3752                                                    const uint8_t *context,
3753                                                    size_t context_len);
3754 
3755 
3756 // Early data.
3757 //
3758 // WARNING: 0-RTT support in BoringSSL is currently experimental and not fully
3759 // implemented. It may cause interoperability or security failures when used.
3760 //
3761 // Early data, or 0-RTT, is a feature in TLS 1.3 which allows clients to send
3762 // data on the first flight during a resumption handshake. This can save a
3763 // round-trip in some application protocols.
3764 //
3765 // WARNING: A 0-RTT handshake has different security properties from normal
3766 // handshake, so it is off by default unless opted in. In particular, early data
3767 // is replayable by a network attacker. Callers must account for this when
3768 // sending or processing data before the handshake is confirmed. See RFC 8446
3769 // for more information.
3770 //
3771 // As a server, if early data is accepted, |SSL_do_handshake| will complete as
3772 // soon as the ClientHello is processed and server flight sent. |SSL_write| may
3773 // be used to send half-RTT data. |SSL_read| will consume early data and
3774 // transition to 1-RTT data as appropriate. Prior to the transition,
3775 // |SSL_in_init| will report the handshake is still in progress. Callers may use
3776 // it or |SSL_in_early_data| to defer or reject requests as needed.
3777 //
3778 // Early data as a client is more complex. If the offered session (see
3779 // |SSL_set_session|) is 0-RTT-capable, the handshake will return after sending
3780 // the ClientHello. The predicted peer certificates and ALPN protocol will be
3781 // available via the usual APIs. |SSL_write| will write early data, up to the
3782 // session's limit. Writes past this limit and |SSL_read| will complete the
3783 // handshake before continuing. Callers may also call |SSL_do_handshake| again
3784 // to complete the handshake sooner.
3785 //
3786 // If the server accepts early data, the handshake will succeed. |SSL_read| and
3787 // |SSL_write| will then act as in a 1-RTT handshake. The peer certificates and
3788 // ALPN protocol will be as predicted and need not be re-queried.
3789 //
3790 // If the server rejects early data, |SSL_do_handshake| (and thus |SSL_read| and
3791 // |SSL_write|) will then fail with |SSL_get_error| returning
3792 // |SSL_ERROR_EARLY_DATA_REJECTED|. The caller should treat this as a connection
3793 // error and most likely perform a high-level retry. Note the server may still
3794 // have processed the early data due to attacker replays.
3795 //
3796 // To then continue the handshake on the original connection, use
3797 // |SSL_reset_early_data_reject|. The connection will then behave as one which
3798 // had not yet completed the handshake. This allows a faster retry than making a
3799 // fresh connection. |SSL_do_handshake| will complete the full handshake,
3800 // possibly resulting in different peer certificates, ALPN protocol, and other
3801 // properties. The caller must disregard any values from before the reset and
3802 // query again.
3803 //
3804 // Finally, to implement the fallback described in RFC 8446 appendix D.3, retry
3805 // on a fresh connection without 0-RTT if the handshake fails with
3806 // |SSL_R_WRONG_VERSION_ON_EARLY_DATA|.
3807 
3808 // SSL_CTX_set_early_data_enabled sets whether early data is allowed to be used
3809 // with resumptions using |ctx|.
3810 OPENSSL_EXPORT void SSL_CTX_set_early_data_enabled(SSL_CTX *ctx, int enabled);
3811 
3812 // SSL_set_early_data_enabled sets whether early data is allowed to be used
3813 // with resumptions using |ssl|. See |SSL_CTX_set_early_data_enabled| for more
3814 // information.
3815 OPENSSL_EXPORT void SSL_set_early_data_enabled(SSL *ssl, int enabled);
3816 
3817 // SSL_in_early_data returns one if |ssl| has a pending handshake that has
3818 // progressed enough to send or receive early data. Clients may call |SSL_write|
3819 // to send early data, but |SSL_read| will complete the handshake before
3820 // accepting application data. Servers may call |SSL_read| to read early data
3821 // and |SSL_write| to send half-RTT data.
3822 OPENSSL_EXPORT int SSL_in_early_data(const SSL *ssl);
3823 
3824 // SSL_SESSION_early_data_capable returns whether early data would have been
3825 // attempted with |session| if enabled.
3826 OPENSSL_EXPORT int SSL_SESSION_early_data_capable(const SSL_SESSION *session);
3827 
3828 // SSL_SESSION_copy_without_early_data returns a copy of |session| with early
3829 // data disabled. If |session| already does not support early data, it returns
3830 // |session| with the reference count increased. The caller takes ownership of
3831 // the result and must release it with |SSL_SESSION_free|.
3832 //
3833 // This function may be used on the client to clear early data support from
3834 // existing sessions when the server rejects early data. In particular,
3835 // |SSL_R_WRONG_VERSION_ON_EARLY_DATA| requires a fresh connection to retry, and
3836 // the client would not want 0-RTT enabled for the next connection attempt.
3837 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_copy_without_early_data(
3838     SSL_SESSION *session);
3839 
3840 // SSL_early_data_accepted returns whether early data was accepted on the
3841 // handshake performed by |ssl|.
3842 OPENSSL_EXPORT int SSL_early_data_accepted(const SSL *ssl);
3843 
3844 // SSL_reset_early_data_reject resets |ssl| after an early data reject. All
3845 // 0-RTT state is discarded, including any pending |SSL_write| calls. The caller
3846 // should treat |ssl| as a logically fresh connection, usually by driving the
3847 // handshake to completion using |SSL_do_handshake|.
3848 //
3849 // It is an error to call this function on an |SSL| object that is not signaling
3850 // |SSL_ERROR_EARLY_DATA_REJECTED|.
3851 OPENSSL_EXPORT void SSL_reset_early_data_reject(SSL *ssl);
3852 
3853 // SSL_get_ticket_age_skew returns the difference, in seconds, between the
3854 // client-sent ticket age and the server-computed value in TLS 1.3 server
3855 // connections which resumed a session.
3856 OPENSSL_EXPORT int32_t SSL_get_ticket_age_skew(const SSL *ssl);
3857 
3858 // An ssl_early_data_reason_t describes why 0-RTT was accepted or rejected.
3859 // These values are persisted to logs. Entries should not be renumbered and
3860 // numeric values should never be reused.
3861 enum ssl_early_data_reason_t BORINGSSL_ENUM_INT {
3862   // The handshake has not progressed far enough for the 0-RTT status to be
3863   // known.
3864   ssl_early_data_unknown = 0,
3865   // 0-RTT is disabled for this connection.
3866   ssl_early_data_disabled = 1,
3867   // 0-RTT was accepted.
3868   ssl_early_data_accepted = 2,
3869   // The negotiated protocol version does not support 0-RTT.
3870   ssl_early_data_protocol_version = 3,
3871   // The peer declined to offer or accept 0-RTT for an unknown reason.
3872   ssl_early_data_peer_declined = 4,
3873   // The client did not offer a session.
3874   ssl_early_data_no_session_offered = 5,
3875   // The server declined to resume the session.
3876   ssl_early_data_session_not_resumed = 6,
3877   // The session does not support 0-RTT.
3878   ssl_early_data_unsupported_for_session = 7,
3879   // The server sent a HelloRetryRequest.
3880   ssl_early_data_hello_retry_request = 8,
3881   // The negotiated ALPN protocol did not match the session.
3882   ssl_early_data_alpn_mismatch = 9,
3883   // The connection negotiated Channel ID, which is incompatible with 0-RTT.
3884   ssl_early_data_channel_id = 10,
3885   // Value 11 is reserved. (It has historically |ssl_early_data_token_binding|.)
3886   // The client and server ticket age were too far apart.
3887   ssl_early_data_ticket_age_skew = 12,
3888   // QUIC parameters differ between this connection and the original.
3889   ssl_early_data_quic_parameter_mismatch = 13,
3890   // The application settings did not match the session.
3891   ssl_early_data_alps_mismatch = 14,
3892   // The value of the largest entry.
3893   ssl_early_data_reason_max_value = ssl_early_data_alps_mismatch,
3894 };
3895 
3896 // SSL_get_early_data_reason returns details why 0-RTT was accepted or rejected
3897 // on |ssl|. This is primarily useful on the server.
3898 OPENSSL_EXPORT enum ssl_early_data_reason_t SSL_get_early_data_reason(
3899     const SSL *ssl);
3900 
3901 // SSL_early_data_reason_string returns a string representation for |reason|, or
3902 // NULL if |reason| is unknown. This function may be used for logging.
3903 OPENSSL_EXPORT const char *SSL_early_data_reason_string(
3904     enum ssl_early_data_reason_t reason);
3905 
3906 
3907 // Encrypted ClientHello.
3908 //
3909 // ECH is a mechanism for encrypting the entire ClientHello message in TLS 1.3.
3910 // This can prevent observers from seeing cleartext information about the
3911 // connection, such as the server_name extension.
3912 //
3913 // By default, BoringSSL will treat the server name, session ticket, and client
3914 // certificate as secret, but most other parameters, such as the ALPN protocol
3915 // list will be treated as public and sent in the cleartext ClientHello. Other
3916 // APIs may be added for applications with different secrecy requirements.
3917 //
3918 // ECH support in BoringSSL is still experimental and under development.
3919 //
3920 // See https://tools.ietf.org/html/draft-ietf-tls-esni-13.
3921 
3922 // SSL_set_enable_ech_grease configures whether the client will send a GREASE
3923 // ECH extension when no supported ECHConfig is available.
3924 OPENSSL_EXPORT void SSL_set_enable_ech_grease(SSL *ssl, int enable);
3925 
3926 // SSL_set1_ech_config_list configures |ssl| to, as a client, offer ECH with the
3927 // specified configuration. |ech_config_list| should contain a serialized
3928 // ECHConfigList structure. It returns one on success and zero on error.
3929 //
3930 // This function returns an error if the input is malformed. If the input is
3931 // valid but none of the ECHConfigs implement supported parameters, it will
3932 // return success and proceed without ECH.
3933 //
3934 // If a supported ECHConfig is found, |ssl| will encrypt the true ClientHello
3935 // parameters. If the server cannot decrypt it, e.g. due to a key mismatch, ECH
3936 // has a recovery flow. |ssl| will handshake using the cleartext parameters,
3937 // including a public name in the ECHConfig. If using
3938 // |SSL_CTX_set_custom_verify|, callers should use |SSL_get0_ech_name_override|
3939 // to verify the certificate with the public name. If using the built-in
3940 // verifier, the |X509_STORE_CTX| will be configured automatically.
3941 //
3942 // If no other errors are found in this handshake, it will fail with
3943 // |SSL_R_ECH_REJECTED|. Since it didn't use the true parameters, the connection
3944 // cannot be used for application data. Instead, callers should handle this
3945 // error by calling |SSL_get0_ech_retry_configs| and retrying the connection
3946 // with updated ECH parameters. If the retry also fails with
3947 // |SSL_R_ECH_REJECTED|, the caller should report a connection failure.
3948 OPENSSL_EXPORT int SSL_set1_ech_config_list(SSL *ssl,
3949                                             const uint8_t *ech_config_list,
3950                                             size_t ech_config_list_len);
3951 
3952 // SSL_get0_ech_name_override, if |ssl| is a client and the server rejected ECH,
3953 // sets |*out_name| and |*out_name_len| to point to a buffer containing the ECH
3954 // public name. Otherwise, the buffer will be empty.
3955 //
3956 // When offering ECH as a client, this function should be called during the
3957 // certificate verification callback (see |SSL_CTX_set_custom_verify|). If
3958 // |*out_name_len| is non-zero, the caller should verify the certificate against
3959 // the result, interpreted as a DNS name, rather than the true server name. In
3960 // this case, the handshake will never succeed and is only used to authenticate
3961 // retry configs. See also |SSL_get0_ech_retry_configs|.
3962 OPENSSL_EXPORT void SSL_get0_ech_name_override(const SSL *ssl,
3963                                                const char **out_name,
3964                                                size_t *out_name_len);
3965 
3966 // SSL_get0_ech_retry_configs sets |*out_retry_configs| and
3967 // |*out_retry_configs_len| to a buffer containing a serialized ECHConfigList.
3968 // If the server did not provide an ECHConfigList, |*out_retry_configs_len| will
3969 // be zero.
3970 //
3971 // When handling an |SSL_R_ECH_REJECTED| error code as a client, callers should
3972 // use this function to recover from potential key mismatches. If the result is
3973 // non-empty, the caller should retry the connection, passing this buffer to
3974 // |SSL_set1_ech_config_list|. If the result is empty, the server has rolled
3975 // back ECH support, and the caller should retry without ECH.
3976 //
3977 // This function must only be called in response to an |SSL_R_ECH_REJECTED|
3978 // error code. Calling this function on |ssl|s that have not authenticated the
3979 // rejection handshake will assert in debug builds and otherwise return an
3980 // unparsable list.
3981 OPENSSL_EXPORT void SSL_get0_ech_retry_configs(
3982     const SSL *ssl, const uint8_t **out_retry_configs,
3983     size_t *out_retry_configs_len);
3984 
3985 // SSL_marshal_ech_config constructs a new serialized ECHConfig. On success, it
3986 // sets |*out| to a newly-allocated buffer containing the result and |*out_len|
3987 // to the size of the buffer. The caller must call |OPENSSL_free| on |*out| to
3988 // release the memory. On failure, it returns zero.
3989 //
3990 // The |config_id| field is a single byte identifier for the ECHConfig. Reusing
3991 // config IDs is allowed, but if multiple ECHConfigs with the same config ID are
3992 // active at a time, server load may increase. See
3993 // |SSL_ECH_KEYS_has_duplicate_config_id|.
3994 //
3995 // The public key and KEM algorithm are taken from |key|. |public_name| is the
3996 // DNS name used to authenticate the recovery flow. |max_name_len| should be the
3997 // length of the longest name in the ECHConfig's anonymity set and influences
3998 // client padding decisions.
3999 OPENSSL_EXPORT int SSL_marshal_ech_config(uint8_t **out, size_t *out_len,
4000                                           uint8_t config_id,
4001                                           const EVP_HPKE_KEY *key,
4002                                           const char *public_name,
4003                                           size_t max_name_len);
4004 
4005 // SSL_ECH_KEYS_new returns a newly-allocated |SSL_ECH_KEYS| or NULL on error.
4006 OPENSSL_EXPORT SSL_ECH_KEYS *SSL_ECH_KEYS_new(void);
4007 
4008 // SSL_ECH_KEYS_up_ref increments the reference count of |keys|.
4009 OPENSSL_EXPORT void SSL_ECH_KEYS_up_ref(SSL_ECH_KEYS *keys);
4010 
4011 // SSL_ECH_KEYS_free releases memory associated with |keys|.
4012 OPENSSL_EXPORT void SSL_ECH_KEYS_free(SSL_ECH_KEYS *keys);
4013 
4014 // SSL_ECH_KEYS_add decodes |ech_config| as an ECHConfig and appends it with
4015 // |key| to |keys|. If |is_retry_config| is non-zero, this config will be
4016 // returned to the client on configuration mismatch. It returns one on success
4017 // and zero on error.
4018 //
4019 // This function should be called successively to register each ECHConfig in
4020 // decreasing order of preference. This configuration must be completed before
4021 // setting |keys| on an |SSL_CTX| with |SSL_CTX_set1_ech_keys|. After that
4022 // point, |keys| is immutable; no more ECHConfig values may be added.
4023 //
4024 // See also |SSL_CTX_set1_ech_keys|.
4025 OPENSSL_EXPORT int SSL_ECH_KEYS_add(SSL_ECH_KEYS *keys, int is_retry_config,
4026                                     const uint8_t *ech_config,
4027                                     size_t ech_config_len,
4028                                     const EVP_HPKE_KEY *key);
4029 
4030 // SSL_ECH_KEYS_has_duplicate_config_id returns one if |keys| has duplicate
4031 // config IDs or zero otherwise. Duplicate config IDs still work, but may
4032 // increase server load due to trial decryption.
4033 OPENSSL_EXPORT int SSL_ECH_KEYS_has_duplicate_config_id(
4034     const SSL_ECH_KEYS *keys);
4035 
4036 // SSL_ECH_KEYS_marshal_retry_configs serializes the retry configs in |keys| as
4037 // an ECHConfigList. On success, it sets |*out| to a newly-allocated buffer
4038 // containing the result and |*out_len| to the size of the buffer. The caller
4039 // must call |OPENSSL_free| on |*out| to release the memory. On failure, it
4040 // returns zero.
4041 //
4042 // This output may be advertised to clients in DNS.
4043 OPENSSL_EXPORT int SSL_ECH_KEYS_marshal_retry_configs(const SSL_ECH_KEYS *keys,
4044                                                       uint8_t **out,
4045                                                       size_t *out_len);
4046 
4047 // SSL_CTX_set1_ech_keys configures |ctx| to use |keys| to decrypt encrypted
4048 // ClientHellos. It returns one on success, and zero on failure. If |keys| does
4049 // not contain any retry configs, this function will fail. Retry configs are
4050 // marked as such when they are added to |keys| with |SSL_ECH_KEYS_add|.
4051 //
4052 // Once |keys| has been passed to this function, it is immutable. Unlike most
4053 // |SSL_CTX| configuration functions, this function may be called even if |ctx|
4054 // already has associated connections on multiple threads. This may be used to
4055 // rotate keys in a long-lived server process.
4056 //
4057 // The configured ECHConfig values should also be advertised out-of-band via DNS
4058 // (see draft-ietf-dnsop-svcb-https). Before advertising an ECHConfig in DNS,
4059 // deployments should ensure all instances of the service are configured with
4060 // the ECHConfig and corresponding private key.
4061 //
4062 // Only the most recent fully-deployed ECHConfigs should be advertised in DNS.
4063 // |keys| may contain a newer set if those ECHConfigs are mid-deployment. It
4064 // should also contain older sets, until the DNS change has rolled out and the
4065 // old records have expired from caches.
4066 //
4067 // If there is a mismatch, |SSL| objects associated with |ctx| will complete the
4068 // handshake using the cleartext ClientHello and send updated ECHConfig values
4069 // to the client. The client will then retry to recover, but with a latency
4070 // penalty. This recovery flow depends on the public name in the ECHConfig.
4071 // Before advertising an ECHConfig in DNS, deployments must ensure all instances
4072 // of the service can present a valid certificate for the public name.
4073 //
4074 // BoringSSL negotiates ECH before certificate selection callbacks are called,
4075 // including |SSL_CTX_set_select_certificate_cb|. If ECH is negotiated, the
4076 // reported |SSL_CLIENT_HELLO| structure and |SSL_get_servername| function will
4077 // transparently reflect the inner ClientHello. Callers should select parameters
4078 // based on these values to correctly handle ECH as well as the recovery flow.
4079 OPENSSL_EXPORT int SSL_CTX_set1_ech_keys(SSL_CTX *ctx, SSL_ECH_KEYS *keys);
4080 
4081 // SSL_ech_accepted returns one if |ssl| negotiated ECH and zero otherwise.
4082 OPENSSL_EXPORT int SSL_ech_accepted(const SSL *ssl);
4083 
4084 
4085 // Alerts.
4086 //
4087 // TLS uses alerts to signal error conditions. Alerts have a type (warning or
4088 // fatal) and description. OpenSSL internally handles fatal alerts with
4089 // dedicated error codes (see |SSL_AD_REASON_OFFSET|). Except for close_notify,
4090 // warning alerts are silently ignored and may only be surfaced with
4091 // |SSL_CTX_set_info_callback|.
4092 
4093 // SSL_AD_REASON_OFFSET is the offset between error reasons and |SSL_AD_*|
4094 // values. Any error code under |ERR_LIB_SSL| with an error reason above this
4095 // value corresponds to an alert description. Consumers may add or subtract
4096 // |SSL_AD_REASON_OFFSET| to convert between them.
4097 //
4098 // make_errors.go reserves error codes above 1000 for manually-assigned errors.
4099 // This value must be kept in sync with reservedReasonCode in make_errors.h
4100 #define SSL_AD_REASON_OFFSET 1000
4101 
4102 // SSL_AD_* are alert descriptions.
4103 #define SSL_AD_CLOSE_NOTIFY SSL3_AD_CLOSE_NOTIFY
4104 #define SSL_AD_UNEXPECTED_MESSAGE SSL3_AD_UNEXPECTED_MESSAGE
4105 #define SSL_AD_BAD_RECORD_MAC SSL3_AD_BAD_RECORD_MAC
4106 #define SSL_AD_DECRYPTION_FAILED TLS1_AD_DECRYPTION_FAILED
4107 #define SSL_AD_RECORD_OVERFLOW TLS1_AD_RECORD_OVERFLOW
4108 #define SSL_AD_DECOMPRESSION_FAILURE SSL3_AD_DECOMPRESSION_FAILURE
4109 #define SSL_AD_HANDSHAKE_FAILURE SSL3_AD_HANDSHAKE_FAILURE
4110 #define SSL_AD_NO_CERTIFICATE SSL3_AD_NO_CERTIFICATE  // Legacy SSL 3.0 value
4111 #define SSL_AD_BAD_CERTIFICATE SSL3_AD_BAD_CERTIFICATE
4112 #define SSL_AD_UNSUPPORTED_CERTIFICATE SSL3_AD_UNSUPPORTED_CERTIFICATE
4113 #define SSL_AD_CERTIFICATE_REVOKED SSL3_AD_CERTIFICATE_REVOKED
4114 #define SSL_AD_CERTIFICATE_EXPIRED SSL3_AD_CERTIFICATE_EXPIRED
4115 #define SSL_AD_CERTIFICATE_UNKNOWN SSL3_AD_CERTIFICATE_UNKNOWN
4116 #define SSL_AD_ILLEGAL_PARAMETER SSL3_AD_ILLEGAL_PARAMETER
4117 #define SSL_AD_UNKNOWN_CA TLS1_AD_UNKNOWN_CA
4118 #define SSL_AD_ACCESS_DENIED TLS1_AD_ACCESS_DENIED
4119 #define SSL_AD_DECODE_ERROR TLS1_AD_DECODE_ERROR
4120 #define SSL_AD_DECRYPT_ERROR TLS1_AD_DECRYPT_ERROR
4121 #define SSL_AD_EXPORT_RESTRICTION TLS1_AD_EXPORT_RESTRICTION
4122 #define SSL_AD_PROTOCOL_VERSION TLS1_AD_PROTOCOL_VERSION
4123 #define SSL_AD_INSUFFICIENT_SECURITY TLS1_AD_INSUFFICIENT_SECURITY
4124 #define SSL_AD_INTERNAL_ERROR TLS1_AD_INTERNAL_ERROR
4125 #define SSL_AD_INAPPROPRIATE_FALLBACK SSL3_AD_INAPPROPRIATE_FALLBACK
4126 #define SSL_AD_USER_CANCELLED TLS1_AD_USER_CANCELLED
4127 #define SSL_AD_NO_RENEGOTIATION TLS1_AD_NO_RENEGOTIATION
4128 #define SSL_AD_MISSING_EXTENSION TLS1_AD_MISSING_EXTENSION
4129 #define SSL_AD_UNSUPPORTED_EXTENSION TLS1_AD_UNSUPPORTED_EXTENSION
4130 #define SSL_AD_CERTIFICATE_UNOBTAINABLE TLS1_AD_CERTIFICATE_UNOBTAINABLE
4131 #define SSL_AD_UNRECOGNIZED_NAME TLS1_AD_UNRECOGNIZED_NAME
4132 #define SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE \
4133   TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE
4134 #define SSL_AD_BAD_CERTIFICATE_HASH_VALUE TLS1_AD_BAD_CERTIFICATE_HASH_VALUE
4135 #define SSL_AD_UNKNOWN_PSK_IDENTITY TLS1_AD_UNKNOWN_PSK_IDENTITY
4136 #define SSL_AD_CERTIFICATE_REQUIRED TLS1_AD_CERTIFICATE_REQUIRED
4137 #define SSL_AD_NO_APPLICATION_PROTOCOL TLS1_AD_NO_APPLICATION_PROTOCOL
4138 #define SSL_AD_ECH_REQUIRED TLS1_AD_ECH_REQUIRED
4139 
4140 // SSL_alert_type_string_long returns a string description of |value| as an
4141 // alert type (warning or fatal).
4142 OPENSSL_EXPORT const char *SSL_alert_type_string_long(int value);
4143 
4144 // SSL_alert_desc_string_long returns a string description of |value| as an
4145 // alert description or "unknown" if unknown.
4146 OPENSSL_EXPORT const char *SSL_alert_desc_string_long(int value);
4147 
4148 // SSL_send_fatal_alert sends a fatal alert over |ssl| of the specified type,
4149 // which should be one of the |SSL_AD_*| constants. It returns one on success
4150 // and <= 0 on error. The caller should pass the return value into
4151 // |SSL_get_error| to determine how to proceed. Once this function has been
4152 // called, future calls to |SSL_write| will fail.
4153 //
4154 // If retrying a failed operation due to |SSL_ERROR_WANT_WRITE|, subsequent
4155 // calls must use the same |alert| parameter.
4156 OPENSSL_EXPORT int SSL_send_fatal_alert(SSL *ssl, uint8_t alert);
4157 
4158 
4159 // ex_data functions.
4160 //
4161 // See |ex_data.h| for details.
4162 
4163 OPENSSL_EXPORT int SSL_set_ex_data(SSL *ssl, int idx, void *data);
4164 OPENSSL_EXPORT void *SSL_get_ex_data(const SSL *ssl, int idx);
4165 OPENSSL_EXPORT int SSL_get_ex_new_index(long argl, void *argp,
4166                                         CRYPTO_EX_unused *unused,
4167                                         CRYPTO_EX_dup *dup_unused,
4168                                         CRYPTO_EX_free *free_func);
4169 
4170 OPENSSL_EXPORT int SSL_SESSION_set_ex_data(SSL_SESSION *session, int idx,
4171                                            void *data);
4172 OPENSSL_EXPORT void *SSL_SESSION_get_ex_data(const SSL_SESSION *session,
4173                                              int idx);
4174 OPENSSL_EXPORT int SSL_SESSION_get_ex_new_index(long argl, void *argp,
4175                                                 CRYPTO_EX_unused *unused,
4176                                                 CRYPTO_EX_dup *dup_unused,
4177                                                 CRYPTO_EX_free *free_func);
4178 
4179 OPENSSL_EXPORT int SSL_CTX_set_ex_data(SSL_CTX *ctx, int idx, void *data);
4180 OPENSSL_EXPORT void *SSL_CTX_get_ex_data(const SSL_CTX *ctx, int idx);
4181 OPENSSL_EXPORT int SSL_CTX_get_ex_new_index(long argl, void *argp,
4182                                             CRYPTO_EX_unused *unused,
4183                                             CRYPTO_EX_dup *dup_unused,
4184                                             CRYPTO_EX_free *free_func);
4185 
4186 OPENSSL_EXPORT int SSL_CREDENTIAL_set_ex_data(SSL_CREDENTIAL *cred, int idx,
4187                                               void *data);
4188 OPENSSL_EXPORT void *SSL_CREDENTIAL_get_ex_data(const SSL_CREDENTIAL *cred,
4189                                                 int idx);
4190 OPENSSL_EXPORT int SSL_CREDENTIAL_get_ex_new_index(long argl, void *argp,
4191                                                    CRYPTO_EX_unused *unused,
4192                                                    CRYPTO_EX_dup *dup_unused,
4193                                                    CRYPTO_EX_free *free_func);
4194 
4195 
4196 // Low-level record-layer state.
4197 
4198 // SSL_get_ivs sets |*out_iv_len| to the length of the IVs for the ciphers
4199 // underlying |ssl| and sets |*out_read_iv| and |*out_write_iv| to point to the
4200 // current IVs for the read and write directions. This is only meaningful for
4201 // connections with implicit IVs (i.e. CBC mode with TLS 1.0).
4202 //
4203 // It returns one on success or zero on error.
4204 OPENSSL_EXPORT int SSL_get_ivs(const SSL *ssl, const uint8_t **out_read_iv,
4205                                const uint8_t **out_write_iv,
4206                                size_t *out_iv_len);
4207 
4208 // SSL_get_key_block_len returns the length of |ssl|'s key block, for TLS 1.2
4209 // and below. It is an error to call this function during a handshake, or if
4210 // |ssl| negotiated TLS 1.3.
4211 OPENSSL_EXPORT size_t SSL_get_key_block_len(const SSL *ssl);
4212 
4213 // SSL_generate_key_block generates |out_len| bytes of key material for |ssl|'s
4214 // current connection state, for TLS 1.2 and below. It is an error to call this
4215 // function during a handshake, or if |ssl| negotiated TLS 1.3.
4216 OPENSSL_EXPORT int SSL_generate_key_block(const SSL *ssl, uint8_t *out,
4217                                           size_t out_len);
4218 
4219 // SSL_get_read_sequence returns, in TLS, the expected sequence number of the
4220 // next incoming record in the current epoch. In DTLS, it returns the maximum
4221 // sequence number received in the current epoch and includes the epoch number
4222 // in the two most significant bytes.
4223 OPENSSL_EXPORT uint64_t SSL_get_read_sequence(const SSL *ssl);
4224 
4225 // SSL_get_write_sequence returns the sequence number of the next outgoing
4226 // record in the current epoch. In DTLS, it includes the epoch number in the
4227 // two most significant bytes.
4228 OPENSSL_EXPORT uint64_t SSL_get_write_sequence(const SSL *ssl);
4229 
4230 // SSL_CTX_set_record_protocol_version returns whether |version| is zero.
4231 OPENSSL_EXPORT int SSL_CTX_set_record_protocol_version(SSL_CTX *ctx,
4232                                                        int version);
4233 
4234 
4235 // Handshake hints.
4236 //
4237 // WARNING: Contact the BoringSSL team before using this API. While this
4238 // mechanism was designed to gracefully recover from version skew and
4239 // configuration mismatch, splitting a single TLS server into multiple services
4240 // is complex.
4241 //
4242 // Some server deployments make asynchronous RPC calls in both ClientHello
4243 // dispatch and private key operations. In TLS handshakes where the private key
4244 // operation occurs in the first round-trip, this results in two consecutive RPC
4245 // round-trips. Handshake hints allow the RPC service to predict a signature.
4246 // If correctly predicted, this can skip the second RPC call.
4247 //
4248 // First, the server installs a certificate selection callback (see
4249 // |SSL_CTX_set_select_certificate_cb|). When that is called, it performs the
4250 // RPC as before, but includes the ClientHello and a capabilities string from
4251 // |SSL_serialize_capabilities|.
4252 //
4253 // Next, the RPC service creates its own |SSL| object, applies the results of
4254 // certificate selection, calls |SSL_request_handshake_hints|, and runs the
4255 // handshake. If this successfully computes handshake hints (see
4256 // |SSL_serialize_handshake_hints|), the RPC server should send the hints
4257 // alongside any certificate selection results.
4258 //
4259 // Finally, the server calls |SSL_set_handshake_hints| and applies any
4260 // configuration from the RPC server. It then completes the handshake as before.
4261 // If the hints apply, BoringSSL will use the predicted signature and skip the
4262 // private key callbacks. Otherwise, BoringSSL will call private key callbacks
4263 // to generate a signature as before.
4264 //
4265 // Callers should synchronize configuration across the two services.
4266 // Configuration mismatches and some cases of version skew are not fatal, but
4267 // may result in the hints not applying. Additionally, some handshake flows use
4268 // the private key in later round-trips, such as TLS 1.3 HelloRetryRequest. In
4269 // those cases, BoringSSL will not predict a signature as there is no benefit.
4270 // Callers must allow for handshakes to complete without a predicted signature.
4271 
4272 // SSL_serialize_capabilities writes an opaque byte string to |out| describing
4273 // some of |ssl|'s capabilities. It returns one on success and zero on error.
4274 //
4275 // This string is used by BoringSSL internally to reduce the impact of version
4276 // skew.
4277 OPENSSL_EXPORT int SSL_serialize_capabilities(const SSL *ssl, CBB *out);
4278 
4279 // SSL_request_handshake_hints configures |ssl| to generate a handshake hint for
4280 // |client_hello|. It returns one on success and zero on error. |client_hello|
4281 // should contain a serialized ClientHello structure, from the |client_hello|
4282 // and |client_hello_len| fields of the |SSL_CLIENT_HELLO| structure.
4283 // |capabilities| should contain the output of |SSL_serialize_capabilities|.
4284 //
4285 // When configured, |ssl| will perform no I/O (so there is no need to configure
4286 // |BIO|s). For QUIC, the caller should still configure an |SSL_QUIC_METHOD|,
4287 // but the callbacks themselves will never be called and may be left NULL or
4288 // report failure. |SSL_provide_quic_data| also should not be called.
4289 //
4290 // If hint generation is successful, |SSL_do_handshake| will stop the handshake
4291 // early with |SSL_get_error| returning |SSL_ERROR_HANDSHAKE_HINTS_READY|. At
4292 // this point, the caller should run |SSL_serialize_handshake_hints| to extract
4293 // the resulting hints.
4294 //
4295 // Hint generation may fail if, e.g., |ssl| was unable to process the
4296 // ClientHello. Callers should then complete the certificate selection RPC and
4297 // continue the original handshake with no hint. It will likely fail, but this
4298 // reports the correct alert to the client and is more robust in case of
4299 // mismatch.
4300 OPENSSL_EXPORT int SSL_request_handshake_hints(SSL *ssl,
4301                                                const uint8_t *client_hello,
4302                                                size_t client_hello_len,
4303                                                const uint8_t *capabilities,
4304                                                size_t capabilities_len);
4305 
4306 // SSL_serialize_handshake_hints writes an opaque byte string to |out|
4307 // containing the handshake hints computed by |out|. It returns one on success
4308 // and zero on error. This function should only be called if
4309 // |SSL_request_handshake_hints| was configured and the handshake terminated
4310 // with |SSL_ERROR_HANDSHAKE_HINTS_READY|.
4311 //
4312 // This string may be passed to |SSL_set_handshake_hints| on another |SSL| to
4313 // avoid an extra signature call.
4314 OPENSSL_EXPORT int SSL_serialize_handshake_hints(const SSL *ssl, CBB *out);
4315 
4316 // SSL_set_handshake_hints configures |ssl| to use |hints| as handshake hints.
4317 // It returns one on success and zero on error. The handshake will then continue
4318 // as before, but apply predicted values from |hints| where applicable.
4319 //
4320 // Hints may contain connection and session secrets, so they must not leak and
4321 // must come from a source trusted to terminate the connection. However, they
4322 // will not change |ssl|'s configuration. The caller is responsible for
4323 // serializing and applying options from the RPC server as needed. This ensures
4324 // |ssl|'s behavior is self-consistent and consistent with the caller's local
4325 // decisions.
4326 OPENSSL_EXPORT int SSL_set_handshake_hints(SSL *ssl, const uint8_t *hints,
4327                                            size_t hints_len);
4328 
4329 
4330 // Obscure functions.
4331 
4332 // SSL_CTX_set_msg_callback installs |cb| as the message callback for |ctx|.
4333 // This callback will be called when sending or receiving low-level record
4334 // headers, complete handshake messages, ChangeCipherSpec, and alerts.
4335 // |write_p| is one for outgoing messages and zero for incoming messages.
4336 //
4337 // For each record header, |cb| is called with |version| = 0 and |content_type|
4338 // = |SSL3_RT_HEADER|. The |len| bytes from |buf| contain the header. Note that
4339 // this does not include the record body. If the record is sealed, the length
4340 // in the header is the length of the ciphertext.
4341 //
4342 // For each handshake message, ChangeCipherSpec, and alert, |version| is the
4343 // protocol version and |content_type| is the corresponding record type. The
4344 // |len| bytes from |buf| contain the handshake message, one-byte
4345 // ChangeCipherSpec body, and two-byte alert, respectively.
4346 //
4347 // In connections that enable ECH, |cb| is additionally called with
4348 // |content_type| = |SSL3_RT_CLIENT_HELLO_INNER| for each ClientHelloInner that
4349 // is encrypted or decrypted. The |len| bytes from |buf| contain the
4350 // ClientHelloInner, including the reconstructed outer extensions and handshake
4351 // header.
4352 //
4353 // For a V2ClientHello, |version| is |SSL2_VERSION|, |content_type| is zero, and
4354 // the |len| bytes from |buf| contain the V2ClientHello structure.
4355 OPENSSL_EXPORT void SSL_CTX_set_msg_callback(
4356     SSL_CTX *ctx, void (*cb)(int is_write, int version, int content_type,
4357                              const void *buf, size_t len, SSL *ssl, void *arg));
4358 
4359 // SSL_CTX_set_msg_callback_arg sets the |arg| parameter of the message
4360 // callback.
4361 OPENSSL_EXPORT void SSL_CTX_set_msg_callback_arg(SSL_CTX *ctx, void *arg);
4362 
4363 // SSL_set_msg_callback installs |cb| as the message callback of |ssl|. See
4364 // |SSL_CTX_set_msg_callback| for when this callback is called.
4365 OPENSSL_EXPORT void SSL_set_msg_callback(
4366     SSL *ssl, void (*cb)(int write_p, int version, int content_type,
4367                          const void *buf, size_t len, SSL *ssl, void *arg));
4368 
4369 // SSL_set_msg_callback_arg sets the |arg| parameter of the message callback.
4370 OPENSSL_EXPORT void SSL_set_msg_callback_arg(SSL *ssl, void *arg);
4371 
4372 // SSL_CTX_set_keylog_callback configures a callback to log key material. This
4373 // is intended for debugging use with tools like Wireshark. The |cb| function
4374 // should log |line| followed by a newline, synchronizing with any concurrent
4375 // access to the log.
4376 //
4377 // The format is described in
4378 // https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format.
4379 OPENSSL_EXPORT void SSL_CTX_set_keylog_callback(
4380     SSL_CTX *ctx, void (*cb)(const SSL *ssl, const char *line));
4381 
4382 // SSL_CTX_get_keylog_callback returns the callback configured by
4383 // |SSL_CTX_set_keylog_callback|.
4384 OPENSSL_EXPORT void (*SSL_CTX_get_keylog_callback(const SSL_CTX *ctx))(
4385     const SSL *ssl, const char *line);
4386 
4387 // SSL_CTX_set_current_time_cb configures a callback to retrieve the current
4388 // time, which should be set in |*out_clock|. This can be used for testing
4389 // purposes; for example, a callback can be configured that returns a time
4390 // set explicitly by the test. The |ssl| pointer passed to |cb| is always null.
4391 OPENSSL_EXPORT void SSL_CTX_set_current_time_cb(
4392     SSL_CTX *ctx, void (*cb)(const SSL *ssl, struct timeval *out_clock));
4393 
4394 // SSL_set_shed_handshake_config allows some of the configuration of |ssl| to be
4395 // freed after its handshake completes.  Once configuration has been shed, APIs
4396 // that query it may fail.  "Configuration" in this context means anything that
4397 // was set by the caller, as distinct from information derived from the
4398 // handshake.  For example, |SSL_get_ciphers| queries how the |SSL| was
4399 // configured by the caller, and fails after configuration has been shed,
4400 // whereas |SSL_get_cipher| queries the result of the handshake, and is
4401 // unaffected by configuration shedding.
4402 //
4403 // If configuration shedding is enabled, it is an error to call |SSL_clear|.
4404 //
4405 // Note that configuration shedding as a client additionally depends on
4406 // renegotiation being disabled (see |SSL_set_renegotiate_mode|). If
4407 // renegotiation is possible, the configuration will be retained. If
4408 // configuration shedding is enabled and renegotiation later disabled after the
4409 // handshake, |SSL_set_renegotiate_mode| will shed configuration then. This may
4410 // be useful for clients which support renegotiation with some ALPN protocols,
4411 // such as HTTP/1.1, and not others, such as HTTP/2.
4412 OPENSSL_EXPORT void SSL_set_shed_handshake_config(SSL *ssl, int enable);
4413 
4414 enum ssl_renegotiate_mode_t BORINGSSL_ENUM_INT {
4415   ssl_renegotiate_never = 0,
4416   ssl_renegotiate_once,
4417   ssl_renegotiate_freely,
4418   ssl_renegotiate_ignore,
4419   ssl_renegotiate_explicit,
4420 };
4421 
4422 // SSL_set_renegotiate_mode configures how |ssl|, a client, reacts to
4423 // renegotiation attempts by a server. If |ssl| is a server, peer-initiated
4424 // renegotiations are *always* rejected and this function does nothing.
4425 //
4426 // WARNING: Renegotiation is error-prone, complicates TLS's security properties,
4427 // and increases its attack surface. When enabled, many common assumptions about
4428 // BoringSSL's behavior no longer hold, and the calling application must handle
4429 // more cases. Renegotiation is also incompatible with many application
4430 // protocols, e.g. section 9.2.1 of RFC 7540. Many functions behave in ambiguous
4431 // or undefined ways during a renegotiation.
4432 //
4433 // The renegotiation mode defaults to |ssl_renegotiate_never|, but may be set
4434 // at any point in a connection's lifetime. Set it to |ssl_renegotiate_once| to
4435 // allow one renegotiation, |ssl_renegotiate_freely| to allow all
4436 // renegotiations or |ssl_renegotiate_ignore| to ignore HelloRequest messages.
4437 // Note that ignoring HelloRequest messages may cause the connection to stall
4438 // if the server waits for the renegotiation to complete.
4439 //
4440 // If set to |ssl_renegotiate_explicit|, |SSL_read| and |SSL_peek| calls which
4441 // encounter a HelloRequest will pause with |SSL_ERROR_WANT_RENEGOTIATE|.
4442 // |SSL_write| will continue to work while paused. The caller may call
4443 // |SSL_renegotiate| to begin the renegotiation at a later point. This mode may
4444 // be used if callers wish to eagerly call |SSL_peek| without triggering a
4445 // renegotiation.
4446 //
4447 // If configuration shedding is enabled (see |SSL_set_shed_handshake_config|),
4448 // configuration is released if, at any point after the handshake, renegotiation
4449 // is disabled. It is not possible to switch from disabling renegotiation to
4450 // enabling it on a given connection. Callers that condition renegotiation on,
4451 // e.g., ALPN must enable renegotiation before the handshake and conditionally
4452 // disable it afterwards.
4453 //
4454 // When enabled, renegotiation can cause properties of |ssl|, such as the cipher
4455 // suite, to change during the lifetime of the connection. More over, during a
4456 // renegotiation, not all properties of the new handshake are available or fully
4457 // established. In BoringSSL, most functions, such as |SSL_get_current_cipher|,
4458 // report information from the most recently completed handshake, not the
4459 // pending one. However, renegotiation may rerun handshake callbacks, such as
4460 // |SSL_CTX_set_cert_cb|. Such callbacks must ensure they are acting on the
4461 // desired versions of each property.
4462 //
4463 // BoringSSL does not reverify peer certificates on renegotiation and instead
4464 // requires they match between handshakes, so certificate verification callbacks
4465 // (see |SSL_CTX_set_custom_verify|) may assume |ssl| is in the initial
4466 // handshake and use |SSL_get0_peer_certificates|, etc.
4467 //
4468 // There is no support in BoringSSL for initiating renegotiations as a client
4469 // or server.
4470 OPENSSL_EXPORT void SSL_set_renegotiate_mode(SSL *ssl,
4471                                              enum ssl_renegotiate_mode_t mode);
4472 
4473 // SSL_renegotiate starts a deferred renegotiation on |ssl| if it was configured
4474 // with |ssl_renegotiate_explicit| and has a pending HelloRequest. It returns
4475 // one on success and zero on error.
4476 //
4477 // This function does not do perform any I/O. On success, a subsequent
4478 // |SSL_do_handshake| call will run the handshake. |SSL_write| and
4479 // |SSL_read| will also complete the handshake before sending or receiving
4480 // application data.
4481 OPENSSL_EXPORT int SSL_renegotiate(SSL *ssl);
4482 
4483 // SSL_renegotiate_pending returns one if |ssl| is in the middle of a
4484 // renegotiation.
4485 OPENSSL_EXPORT int SSL_renegotiate_pending(SSL *ssl);
4486 
4487 // SSL_total_renegotiations returns the total number of renegotiation handshakes
4488 // performed by |ssl|. This includes the pending renegotiation, if any.
4489 OPENSSL_EXPORT int SSL_total_renegotiations(const SSL *ssl);
4490 
4491 // SSL_MAX_CERT_LIST_DEFAULT is the default maximum length, in bytes, of a peer
4492 // certificate chain.
4493 #define SSL_MAX_CERT_LIST_DEFAULT (1024 * 100)
4494 
4495 // SSL_CTX_get_max_cert_list returns the maximum length, in bytes, of a peer
4496 // certificate chain accepted by |ctx|.
4497 OPENSSL_EXPORT size_t SSL_CTX_get_max_cert_list(const SSL_CTX *ctx);
4498 
4499 // SSL_CTX_set_max_cert_list sets the maximum length, in bytes, of a peer
4500 // certificate chain to |max_cert_list|. This affects how much memory may be
4501 // consumed during the handshake.
4502 OPENSSL_EXPORT void SSL_CTX_set_max_cert_list(SSL_CTX *ctx,
4503                                               size_t max_cert_list);
4504 
4505 // SSL_get_max_cert_list returns the maximum length, in bytes, of a peer
4506 // certificate chain accepted by |ssl|.
4507 OPENSSL_EXPORT size_t SSL_get_max_cert_list(const SSL *ssl);
4508 
4509 // SSL_set_max_cert_list sets the maximum length, in bytes, of a peer
4510 // certificate chain to |max_cert_list|. This affects how much memory may be
4511 // consumed during the handshake.
4512 OPENSSL_EXPORT void SSL_set_max_cert_list(SSL *ssl, size_t max_cert_list);
4513 
4514 // SSL_CTX_set_max_send_fragment sets the maximum length, in bytes, of records
4515 // sent by |ctx|. Beyond this length, handshake messages and application data
4516 // will be split into multiple records. It returns one on success or zero on
4517 // error.
4518 OPENSSL_EXPORT int SSL_CTX_set_max_send_fragment(SSL_CTX *ctx,
4519                                                  size_t max_send_fragment);
4520 
4521 // SSL_set_max_send_fragment sets the maximum length, in bytes, of records sent
4522 // by |ssl|. Beyond this length, handshake messages and application data will
4523 // be split into multiple records. It returns one on success or zero on
4524 // error.
4525 OPENSSL_EXPORT int SSL_set_max_send_fragment(SSL *ssl,
4526                                              size_t max_send_fragment);
4527 
4528 // ssl_early_callback_ctx (aka |SSL_CLIENT_HELLO|) is passed to certain
4529 // callbacks that are called very early on during the server handshake. At this
4530 // point, much of the SSL* hasn't been filled out and only the ClientHello can
4531 // be depended on.
4532 struct ssl_early_callback_ctx {
4533   SSL *ssl;
4534   const uint8_t *client_hello;
4535   size_t client_hello_len;
4536   uint16_t version;
4537   const uint8_t *random;
4538   size_t random_len;
4539   const uint8_t *session_id;
4540   size_t session_id_len;
4541   const uint8_t *cipher_suites;
4542   size_t cipher_suites_len;
4543   const uint8_t *compression_methods;
4544   size_t compression_methods_len;
4545   const uint8_t *extensions;
4546   size_t extensions_len;
4547 } /* SSL_CLIENT_HELLO */;
4548 
4549 // ssl_select_cert_result_t enumerates the possible results from selecting a
4550 // certificate with |select_certificate_cb|.
4551 enum ssl_select_cert_result_t BORINGSSL_ENUM_INT {
4552   // ssl_select_cert_success indicates that the certificate selection was
4553   // successful.
4554   ssl_select_cert_success = 1,
4555   // ssl_select_cert_retry indicates that the operation could not be
4556   // immediately completed and must be reattempted at a later point.
4557   ssl_select_cert_retry = 0,
4558   // ssl_select_cert_error indicates that a fatal error occured and the
4559   // handshake should be terminated.
4560   ssl_select_cert_error = -1,
4561 };
4562 
4563 // SSL_early_callback_ctx_extension_get searches the extensions in
4564 // |client_hello| for an extension of the given type. If not found, it returns
4565 // zero. Otherwise it sets |out_data| to point to the extension contents (not
4566 // including the type and length bytes), sets |out_len| to the length of the
4567 // extension contents and returns one.
4568 OPENSSL_EXPORT int SSL_early_callback_ctx_extension_get(
4569     const SSL_CLIENT_HELLO *client_hello, uint16_t extension_type,
4570     const uint8_t **out_data, size_t *out_len);
4571 
4572 // SSL_CTX_set_select_certificate_cb sets a callback that is called before most
4573 // ClientHello processing and before the decision whether to resume a session
4574 // is made. The callback may inspect the ClientHello and configure the
4575 // connection. See |ssl_select_cert_result_t| for details of the return values.
4576 //
4577 // In the case that a retry is indicated, |SSL_get_error| will return
4578 // |SSL_ERROR_PENDING_CERTIFICATE| and the caller should arrange for the
4579 // high-level operation on |ssl| to be retried at a later time, which will
4580 // result in another call to |cb|.
4581 //
4582 // |SSL_get_servername| may be used during this callback.
4583 //
4584 // Note: The |SSL_CLIENT_HELLO| is only valid for the duration of the callback
4585 // and is not valid while the handshake is paused.
4586 OPENSSL_EXPORT void SSL_CTX_set_select_certificate_cb(
4587     SSL_CTX *ctx,
4588     enum ssl_select_cert_result_t (*cb)(const SSL_CLIENT_HELLO *));
4589 
4590 // SSL_CTX_set_dos_protection_cb sets a callback that is called once the
4591 // resumption decision for a ClientHello has been made. It can return one to
4592 // allow the handshake to continue or zero to cause the handshake to abort.
4593 OPENSSL_EXPORT void SSL_CTX_set_dos_protection_cb(
4594     SSL_CTX *ctx, int (*cb)(const SSL_CLIENT_HELLO *));
4595 
4596 // SSL_CTX_set_reverify_on_resume configures whether the certificate
4597 // verification callback will be used to reverify stored certificates
4598 // when resuming a session. This only works with |SSL_CTX_set_custom_verify|.
4599 // For now, this is incompatible with |SSL_VERIFY_NONE| mode, and is only
4600 // respected on clients.
4601 OPENSSL_EXPORT void SSL_CTX_set_reverify_on_resume(SSL_CTX *ctx, int enabled);
4602 
4603 // SSL_set_enforce_rsa_key_usage configures whether, when |ssl| is a client
4604 // negotiating TLS 1.2 or below, the keyUsage extension of RSA leaf server
4605 // certificates will be checked for consistency with the TLS usage. In all other
4606 // cases, this check is always enabled.
4607 //
4608 // This parameter may be set late; it will not be read until after the
4609 // certificate verification callback.
4610 OPENSSL_EXPORT void SSL_set_enforce_rsa_key_usage(SSL *ssl, int enabled);
4611 
4612 // SSL_was_key_usage_invalid returns one if |ssl|'s handshake succeeded despite
4613 // using TLS parameters which were incompatible with the leaf certificate's
4614 // keyUsage extension. Otherwise, it returns zero.
4615 //
4616 // If |SSL_set_enforce_rsa_key_usage| is enabled or not applicable, this
4617 // function will always return zero because key usages will be consistently
4618 // checked.
4619 OPENSSL_EXPORT int SSL_was_key_usage_invalid(const SSL *ssl);
4620 
4621 // SSL_ST_* are possible values for |SSL_state|, the bitmasks that make them up,
4622 // and some historical values for compatibility. Only |SSL_ST_INIT| and
4623 // |SSL_ST_OK| are ever returned.
4624 #define SSL_ST_CONNECT 0x1000
4625 #define SSL_ST_ACCEPT 0x2000
4626 #define SSL_ST_MASK 0x0FFF
4627 #define SSL_ST_INIT (SSL_ST_CONNECT | SSL_ST_ACCEPT)
4628 #define SSL_ST_OK 0x03
4629 #define SSL_ST_RENEGOTIATE (0x04 | SSL_ST_INIT)
4630 #define SSL_ST_BEFORE (0x05 | SSL_ST_INIT)
4631 
4632 // TLS_ST_* are aliases for |SSL_ST_*| for OpenSSL 1.1.0 compatibility.
4633 #define TLS_ST_OK SSL_ST_OK
4634 #define TLS_ST_BEFORE SSL_ST_BEFORE
4635 
4636 // SSL_CB_* are possible values for the |type| parameter in the info
4637 // callback and the bitmasks that make them up.
4638 #define SSL_CB_LOOP 0x01
4639 #define SSL_CB_EXIT 0x02
4640 #define SSL_CB_READ 0x04
4641 #define SSL_CB_WRITE 0x08
4642 #define SSL_CB_ALERT 0x4000
4643 #define SSL_CB_READ_ALERT (SSL_CB_ALERT | SSL_CB_READ)
4644 #define SSL_CB_WRITE_ALERT (SSL_CB_ALERT | SSL_CB_WRITE)
4645 #define SSL_CB_ACCEPT_LOOP (SSL_ST_ACCEPT | SSL_CB_LOOP)
4646 #define SSL_CB_ACCEPT_EXIT (SSL_ST_ACCEPT | SSL_CB_EXIT)
4647 #define SSL_CB_CONNECT_LOOP (SSL_ST_CONNECT | SSL_CB_LOOP)
4648 #define SSL_CB_CONNECT_EXIT (SSL_ST_CONNECT | SSL_CB_EXIT)
4649 #define SSL_CB_HANDSHAKE_START 0x10
4650 #define SSL_CB_HANDSHAKE_DONE 0x20
4651 
4652 // SSL_CTX_set_info_callback configures a callback to be run when various
4653 // events occur during a connection's lifetime. The |type| argument determines
4654 // the type of event and the meaning of the |value| argument. Callbacks must
4655 // ignore unexpected |type| values.
4656 //
4657 // |SSL_CB_READ_ALERT| is signaled for each alert received, warning or fatal.
4658 // The |value| argument is a 16-bit value where the alert level (either
4659 // |SSL3_AL_WARNING| or |SSL3_AL_FATAL|) is in the most-significant eight bits
4660 // and the alert type (one of |SSL_AD_*|) is in the least-significant eight.
4661 //
4662 // |SSL_CB_WRITE_ALERT| is signaled for each alert sent. The |value| argument
4663 // is constructed as with |SSL_CB_READ_ALERT|.
4664 //
4665 // |SSL_CB_HANDSHAKE_START| is signaled when a handshake begins. The |value|
4666 // argument is always one.
4667 //
4668 // |SSL_CB_HANDSHAKE_DONE| is signaled when a handshake completes successfully.
4669 // The |value| argument is always one. If a handshake False Starts, this event
4670 // may be used to determine when the Finished message is received.
4671 //
4672 // The following event types expose implementation details of the handshake
4673 // state machine. Consuming them is deprecated.
4674 //
4675 // |SSL_CB_ACCEPT_LOOP| (respectively, |SSL_CB_CONNECT_LOOP|) is signaled when
4676 // a server (respectively, client) handshake progresses. The |value| argument
4677 // is always one.
4678 //
4679 // |SSL_CB_ACCEPT_EXIT| (respectively, |SSL_CB_CONNECT_EXIT|) is signaled when
4680 // a server (respectively, client) handshake completes, fails, or is paused.
4681 // The |value| argument is one if the handshake succeeded and <= 0
4682 // otherwise.
4683 OPENSSL_EXPORT void SSL_CTX_set_info_callback(
4684     SSL_CTX *ctx, void (*cb)(const SSL *ssl, int type, int value));
4685 
4686 // SSL_CTX_get_info_callback returns the callback set by
4687 // |SSL_CTX_set_info_callback|.
4688 OPENSSL_EXPORT void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl,
4689                                                                int type,
4690                                                                int value);
4691 
4692 // SSL_set_info_callback configures a callback to be run at various events
4693 // during a connection's lifetime. See |SSL_CTX_set_info_callback|.
4694 OPENSSL_EXPORT void SSL_set_info_callback(
4695     SSL *ssl, void (*cb)(const SSL *ssl, int type, int value));
4696 
4697 // SSL_get_info_callback returns the callback set by |SSL_set_info_callback|.
4698 OPENSSL_EXPORT void (*SSL_get_info_callback(const SSL *ssl))(const SSL *ssl,
4699                                                              int type,
4700                                                              int value);
4701 
4702 // SSL_state_string_long returns the current state of the handshake state
4703 // machine as a string. This may be useful for debugging and logging.
4704 OPENSSL_EXPORT const char *SSL_state_string_long(const SSL *ssl);
4705 
4706 #define SSL_SENT_SHUTDOWN 1
4707 #define SSL_RECEIVED_SHUTDOWN 2
4708 
4709 // SSL_get_shutdown returns a bitmask with a subset of |SSL_SENT_SHUTDOWN| and
4710 // |SSL_RECEIVED_SHUTDOWN| to query whether close_notify was sent or received,
4711 // respectively.
4712 OPENSSL_EXPORT int SSL_get_shutdown(const SSL *ssl);
4713 
4714 // SSL_get_peer_signature_algorithm returns the signature algorithm used by the
4715 // peer. If not applicable, it returns zero.
4716 OPENSSL_EXPORT uint16_t SSL_get_peer_signature_algorithm(const SSL *ssl);
4717 
4718 // SSL_get_client_random writes up to |max_out| bytes of the most recent
4719 // handshake's client_random to |out| and returns the number of bytes written.
4720 // If |max_out| is zero, it returns the size of the client_random.
4721 OPENSSL_EXPORT size_t SSL_get_client_random(const SSL *ssl, uint8_t *out,
4722                                             size_t max_out);
4723 
4724 // SSL_get_server_random writes up to |max_out| bytes of the most recent
4725 // handshake's server_random to |out| and returns the number of bytes written.
4726 // If |max_out| is zero, it returns the size of the server_random.
4727 OPENSSL_EXPORT size_t SSL_get_server_random(const SSL *ssl, uint8_t *out,
4728                                             size_t max_out);
4729 
4730 // SSL_get_pending_cipher returns the cipher suite for the current handshake or
4731 // NULL if one has not been negotiated yet or there is no pending handshake.
4732 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_pending_cipher(const SSL *ssl);
4733 
4734 // SSL_set_retain_only_sha256_of_client_certs, on a server, sets whether only
4735 // the SHA-256 hash of peer's certificate should be saved in memory and in the
4736 // session. This can save memory, ticket size and session cache space. If
4737 // enabled, |SSL_get_peer_certificate| will return NULL after the handshake
4738 // completes. See |SSL_SESSION_has_peer_sha256| and
4739 // |SSL_SESSION_get0_peer_sha256| to query the hash.
4740 OPENSSL_EXPORT void SSL_set_retain_only_sha256_of_client_certs(SSL *ssl,
4741                                                                int enable);
4742 
4743 // SSL_CTX_set_retain_only_sha256_of_client_certs, on a server, sets whether
4744 // only the SHA-256 hash of peer's certificate should be saved in memory and in
4745 // the session. This can save memory, ticket size and session cache space. If
4746 // enabled, |SSL_get_peer_certificate| will return NULL after the handshake
4747 // completes. See |SSL_SESSION_has_peer_sha256| and
4748 // |SSL_SESSION_get0_peer_sha256| to query the hash.
4749 OPENSSL_EXPORT void SSL_CTX_set_retain_only_sha256_of_client_certs(SSL_CTX *ctx,
4750                                                                    int enable);
4751 
4752 // SSL_CTX_set_grease_enabled configures whether sockets on |ctx| should enable
4753 // GREASE. See RFC 8701.
4754 OPENSSL_EXPORT void SSL_CTX_set_grease_enabled(SSL_CTX *ctx, int enabled);
4755 
4756 // SSL_CTX_set_permute_extensions configures whether sockets on |ctx| should
4757 // permute extensions. For now, this is only implemented for the ClientHello.
4758 OPENSSL_EXPORT void SSL_CTX_set_permute_extensions(SSL_CTX *ctx, int enabled);
4759 
4760 // SSL_set_permute_extensions configures whether sockets on |ssl| should
4761 // permute extensions. For now, this is only implemented for the ClientHello.
4762 OPENSSL_EXPORT void SSL_set_permute_extensions(SSL *ssl, int enabled);
4763 
4764 // SSL_max_seal_overhead returns the maximum overhead, in bytes, of sealing a
4765 // record with |ssl|.
4766 OPENSSL_EXPORT size_t SSL_max_seal_overhead(const SSL *ssl);
4767 
4768 // SSL_CTX_set_false_start_allowed_without_alpn configures whether connections
4769 // on |ctx| may use False Start (if |SSL_MODE_ENABLE_FALSE_START| is enabled)
4770 // without negotiating ALPN.
4771 OPENSSL_EXPORT void SSL_CTX_set_false_start_allowed_without_alpn(SSL_CTX *ctx,
4772                                                                  int allowed);
4773 
4774 // SSL_used_hello_retry_request returns one if the TLS 1.3 HelloRetryRequest
4775 // message has been either sent by the server or received by the client. It
4776 // returns zero otherwise.
4777 OPENSSL_EXPORT int SSL_used_hello_retry_request(const SSL *ssl);
4778 
4779 // SSL_set_jdk11_workaround configures whether to workaround various bugs in
4780 // JDK 11's TLS 1.3 implementation by disabling TLS 1.3 for such clients.
4781 //
4782 // https://bugs.openjdk.java.net/browse/JDK-8211806
4783 // https://bugs.openjdk.java.net/browse/JDK-8212885
4784 // https://bugs.openjdk.java.net/browse/JDK-8213202
4785 OPENSSL_EXPORT void SSL_set_jdk11_workaround(SSL *ssl, int enable);
4786 
4787 // SSL_set_check_client_certificate_type configures whether the client, in
4788 // TLS 1.2 and below, will check its certificate against the server's requested
4789 // certificate types.
4790 //
4791 // By default, this option is enabled. If disabled, certificate selection within
4792 // the library may not function correctly. This flag is provided temporarily in
4793 // case of compatibility issues. It will be removed sometime after June 2024.
4794 OPENSSL_EXPORT void SSL_set_check_client_certificate_type(SSL *ssl, int enable);
4795 
4796 // SSL_set_check_ecdsa_curve configures whether the server, in TLS 1.2 and
4797 // below, will check its certificate against the client's supported ECDSA
4798 // curves.
4799 //
4800 // By default, this option is enabled. If disabled, certificate selection within
4801 // the library may not function correctly. This flag is provided temporarily in
4802 // case of compatibility issues. It will be removed sometime after June 2024.
4803 OPENSSL_EXPORT void SSL_set_check_ecdsa_curve(SSL *ssl, int enable);
4804 
4805 
4806 // Deprecated functions.
4807 
4808 // SSL_library_init calls |CRYPTO_library_init| and returns one.
4809 OPENSSL_EXPORT int SSL_library_init(void);
4810 
4811 // SSL_CIPHER_description writes a description of |cipher| into |buf| and
4812 // returns |buf|. If |buf| is NULL, it returns a newly allocated string, to be
4813 // freed with |OPENSSL_free|, or NULL on error.
4814 //
4815 // The description includes a trailing newline and has the form:
4816 // AES128-SHA              Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA1
4817 //
4818 // Consider |SSL_CIPHER_standard_name| or |SSL_CIPHER_get_name| instead.
4819 OPENSSL_EXPORT const char *SSL_CIPHER_description(const SSL_CIPHER *cipher,
4820                                                   char *buf, int len);
4821 
4822 // SSL_CIPHER_get_version returns the string "TLSv1/SSLv3".
4823 OPENSSL_EXPORT const char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher);
4824 
4825 typedef void COMP_METHOD;
4826 typedef struct ssl_comp_st SSL_COMP;
4827 
4828 // SSL_COMP_get_compression_methods returns NULL.
4829 OPENSSL_EXPORT STACK_OF(SSL_COMP) *SSL_COMP_get_compression_methods(void);
4830 
4831 // SSL_COMP_add_compression_method returns one.
4832 OPENSSL_EXPORT int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm);
4833 
4834 // SSL_COMP_get_name returns NULL.
4835 OPENSSL_EXPORT const char *SSL_COMP_get_name(const COMP_METHOD *comp);
4836 
4837 // SSL_COMP_get0_name returns the |name| member of |comp|.
4838 OPENSSL_EXPORT const char *SSL_COMP_get0_name(const SSL_COMP *comp);
4839 
4840 // SSL_COMP_get_id returns the |id| member of |comp|.
4841 OPENSSL_EXPORT int SSL_COMP_get_id(const SSL_COMP *comp);
4842 
4843 // SSL_COMP_free_compression_methods does nothing.
4844 OPENSSL_EXPORT void SSL_COMP_free_compression_methods(void);
4845 
4846 // SSLv23_method calls |TLS_method|.
4847 OPENSSL_EXPORT const SSL_METHOD *SSLv23_method(void);
4848 
4849 // These version-specific methods behave exactly like |TLS_method| and
4850 // |DTLS_method| except they also call |SSL_CTX_set_min_proto_version| and
4851 // |SSL_CTX_set_max_proto_version| to lock connections to that protocol
4852 // version.
4853 OPENSSL_EXPORT const SSL_METHOD *TLSv1_method(void);
4854 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_method(void);
4855 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_method(void);
4856 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_method(void);
4857 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_method(void);
4858 
4859 // These client- and server-specific methods call their corresponding generic
4860 // methods.
4861 OPENSSL_EXPORT const SSL_METHOD *TLS_server_method(void);
4862 OPENSSL_EXPORT const SSL_METHOD *TLS_client_method(void);
4863 OPENSSL_EXPORT const SSL_METHOD *SSLv23_server_method(void);
4864 OPENSSL_EXPORT const SSL_METHOD *SSLv23_client_method(void);
4865 OPENSSL_EXPORT const SSL_METHOD *TLSv1_server_method(void);
4866 OPENSSL_EXPORT const SSL_METHOD *TLSv1_client_method(void);
4867 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_server_method(void);
4868 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_client_method(void);
4869 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_server_method(void);
4870 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_client_method(void);
4871 OPENSSL_EXPORT const SSL_METHOD *DTLS_server_method(void);
4872 OPENSSL_EXPORT const SSL_METHOD *DTLS_client_method(void);
4873 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_server_method(void);
4874 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_client_method(void);
4875 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_server_method(void);
4876 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_client_method(void);
4877 
4878 // SSL_clear resets |ssl| to allow another connection and returns one on success
4879 // or zero on failure. It returns most configuration state but releases memory
4880 // associated with the current connection.
4881 //
4882 // Free |ssl| and create a new one instead.
4883 OPENSSL_EXPORT int SSL_clear(SSL *ssl);
4884 
4885 // SSL_CTX_set_tmp_rsa_callback does nothing.
4886 OPENSSL_EXPORT void SSL_CTX_set_tmp_rsa_callback(
4887     SSL_CTX *ctx, RSA *(*cb)(SSL *ssl, int is_export, int keylength));
4888 
4889 // SSL_set_tmp_rsa_callback does nothing.
4890 OPENSSL_EXPORT void SSL_set_tmp_rsa_callback(SSL *ssl,
4891                                              RSA *(*cb)(SSL *ssl, int is_export,
4892                                                         int keylength));
4893 
4894 // SSL_CTX_sess_connect returns zero.
4895 OPENSSL_EXPORT int SSL_CTX_sess_connect(const SSL_CTX *ctx);
4896 
4897 // SSL_CTX_sess_connect_good returns zero.
4898 OPENSSL_EXPORT int SSL_CTX_sess_connect_good(const SSL_CTX *ctx);
4899 
4900 // SSL_CTX_sess_connect_renegotiate returns zero.
4901 OPENSSL_EXPORT int SSL_CTX_sess_connect_renegotiate(const SSL_CTX *ctx);
4902 
4903 // SSL_CTX_sess_accept returns zero.
4904 OPENSSL_EXPORT int SSL_CTX_sess_accept(const SSL_CTX *ctx);
4905 
4906 // SSL_CTX_sess_accept_renegotiate returns zero.
4907 OPENSSL_EXPORT int SSL_CTX_sess_accept_renegotiate(const SSL_CTX *ctx);
4908 
4909 // SSL_CTX_sess_accept_good returns zero.
4910 OPENSSL_EXPORT int SSL_CTX_sess_accept_good(const SSL_CTX *ctx);
4911 
4912 // SSL_CTX_sess_hits returns zero.
4913 OPENSSL_EXPORT int SSL_CTX_sess_hits(const SSL_CTX *ctx);
4914 
4915 // SSL_CTX_sess_cb_hits returns zero.
4916 OPENSSL_EXPORT int SSL_CTX_sess_cb_hits(const SSL_CTX *ctx);
4917 
4918 // SSL_CTX_sess_misses returns zero.
4919 OPENSSL_EXPORT int SSL_CTX_sess_misses(const SSL_CTX *ctx);
4920 
4921 // SSL_CTX_sess_timeouts returns zero.
4922 OPENSSL_EXPORT int SSL_CTX_sess_timeouts(const SSL_CTX *ctx);
4923 
4924 // SSL_CTX_sess_cache_full returns zero.
4925 OPENSSL_EXPORT int SSL_CTX_sess_cache_full(const SSL_CTX *ctx);
4926 
4927 // SSL_cutthrough_complete calls |SSL_in_false_start|.
4928 OPENSSL_EXPORT int SSL_cutthrough_complete(const SSL *ssl);
4929 
4930 // SSL_num_renegotiations calls |SSL_total_renegotiations|.
4931 OPENSSL_EXPORT int SSL_num_renegotiations(const SSL *ssl);
4932 
4933 // SSL_CTX_need_tmp_RSA returns zero.
4934 OPENSSL_EXPORT int SSL_CTX_need_tmp_RSA(const SSL_CTX *ctx);
4935 
4936 // SSL_need_tmp_RSA returns zero.
4937 OPENSSL_EXPORT int SSL_need_tmp_RSA(const SSL *ssl);
4938 
4939 // SSL_CTX_set_tmp_rsa returns one.
4940 OPENSSL_EXPORT int SSL_CTX_set_tmp_rsa(SSL_CTX *ctx, const RSA *rsa);
4941 
4942 // SSL_set_tmp_rsa returns one.
4943 OPENSSL_EXPORT int SSL_set_tmp_rsa(SSL *ssl, const RSA *rsa);
4944 
4945 // SSL_CTX_get_read_ahead returns zero.
4946 OPENSSL_EXPORT int SSL_CTX_get_read_ahead(const SSL_CTX *ctx);
4947 
4948 // SSL_CTX_set_read_ahead returns one.
4949 OPENSSL_EXPORT int SSL_CTX_set_read_ahead(SSL_CTX *ctx, int yes);
4950 
4951 // SSL_get_read_ahead returns zero.
4952 OPENSSL_EXPORT int SSL_get_read_ahead(const SSL *ssl);
4953 
4954 // SSL_set_read_ahead returns one.
4955 OPENSSL_EXPORT int SSL_set_read_ahead(SSL *ssl, int yes);
4956 
4957 // SSL_set_state does nothing.
4958 OPENSSL_EXPORT void SSL_set_state(SSL *ssl, int state);
4959 
4960 // SSL_get_shared_ciphers writes an empty string to |buf| and returns a
4961 // pointer to |buf|, or NULL if |len| is less than or equal to zero.
4962 OPENSSL_EXPORT char *SSL_get_shared_ciphers(const SSL *ssl, char *buf, int len);
4963 
4964 // SSL_get_shared_sigalgs returns zero.
4965 OPENSSL_EXPORT int SSL_get_shared_sigalgs(SSL *ssl, int idx, int *psign,
4966                                           int *phash, int *psignandhash,
4967                                           uint8_t *rsig, uint8_t *rhash);
4968 
4969 // SSL_MODE_HANDSHAKE_CUTTHROUGH is the same as SSL_MODE_ENABLE_FALSE_START.
4970 #define SSL_MODE_HANDSHAKE_CUTTHROUGH SSL_MODE_ENABLE_FALSE_START
4971 
4972 // i2d_SSL_SESSION serializes |in|, as described in |i2d_SAMPLE|.
4973 //
4974 // Use |SSL_SESSION_to_bytes| instead.
4975 OPENSSL_EXPORT int i2d_SSL_SESSION(SSL_SESSION *in, uint8_t **pp);
4976 
4977 // d2i_SSL_SESSION parses a serialized session from the |length| bytes pointed
4978 // to by |*pp|, as described in |d2i_SAMPLE|.
4979 //
4980 // Use |SSL_SESSION_from_bytes| instead.
4981 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a, const uint8_t **pp,
4982                                             long length);
4983 
4984 // i2d_SSL_SESSION_bio serializes |session| and writes the result to |bio|. It
4985 // returns the number of bytes written on success and <= 0 on error.
4986 OPENSSL_EXPORT int i2d_SSL_SESSION_bio(BIO *bio, const SSL_SESSION *session);
4987 
4988 // d2i_SSL_SESSION_bio reads a serialized |SSL_SESSION| from |bio| and returns a
4989 // newly-allocated |SSL_SESSION| or NULL on error. If |out| is not NULL, it also
4990 // frees |*out| and sets |*out| to the new |SSL_SESSION|.
4991 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION_bio(BIO *bio, SSL_SESSION **out);
4992 
4993 // ERR_load_SSL_strings does nothing.
4994 OPENSSL_EXPORT void ERR_load_SSL_strings(void);
4995 
4996 // SSL_load_error_strings does nothing.
4997 OPENSSL_EXPORT void SSL_load_error_strings(void);
4998 
4999 // SSL_CTX_set_tlsext_use_srtp calls |SSL_CTX_set_srtp_profiles|. It returns
5000 // zero on success and one on failure.
5001 //
5002 // WARNING: this function is dangerous because it breaks the usual return value
5003 // convention. Use |SSL_CTX_set_srtp_profiles| instead.
5004 OPENSSL_EXPORT int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx,
5005                                                const char *profiles);
5006 
5007 // SSL_set_tlsext_use_srtp calls |SSL_set_srtp_profiles|. It returns zero on
5008 // success and one on failure.
5009 //
5010 // WARNING: this function is dangerous because it breaks the usual return value
5011 // convention. Use |SSL_set_srtp_profiles| instead.
5012 OPENSSL_EXPORT int SSL_set_tlsext_use_srtp(SSL *ssl, const char *profiles);
5013 
5014 // SSL_get_current_compression returns NULL.
5015 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_compression(SSL *ssl);
5016 
5017 // SSL_get_current_expansion returns NULL.
5018 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_expansion(SSL *ssl);
5019 
5020 // SSL_get_server_tmp_key returns zero.
5021 OPENSSL_EXPORT int SSL_get_server_tmp_key(SSL *ssl, EVP_PKEY **out_key);
5022 
5023 // SSL_CTX_set_tmp_dh returns 1.
5024 OPENSSL_EXPORT int SSL_CTX_set_tmp_dh(SSL_CTX *ctx, const DH *dh);
5025 
5026 // SSL_set_tmp_dh returns 1.
5027 OPENSSL_EXPORT int SSL_set_tmp_dh(SSL *ssl, const DH *dh);
5028 
5029 // SSL_CTX_set_tmp_dh_callback does nothing.
5030 OPENSSL_EXPORT void SSL_CTX_set_tmp_dh_callback(
5031     SSL_CTX *ctx, DH *(*cb)(SSL *ssl, int is_export, int keylength));
5032 
5033 // SSL_set_tmp_dh_callback does nothing.
5034 OPENSSL_EXPORT void SSL_set_tmp_dh_callback(SSL *ssl,
5035                                             DH *(*cb)(SSL *ssl, int is_export,
5036                                                       int keylength));
5037 
5038 // SSL_CTX_set1_sigalgs takes |num_values| ints and interprets them as pairs
5039 // where the first is the nid of a hash function and the second is an
5040 // |EVP_PKEY_*| value. It configures the signature algorithm preferences for
5041 // |ctx| based on them and returns one on success or zero on error.
5042 //
5043 // This API is compatible with OpenSSL. However, BoringSSL-specific code should
5044 // prefer |SSL_CTX_set_signing_algorithm_prefs| because it's clearer and it's
5045 // more convenient to codesearch for specific algorithm values.
5046 OPENSSL_EXPORT int SSL_CTX_set1_sigalgs(SSL_CTX *ctx, const int *values,
5047                                         size_t num_values);
5048 
5049 // SSL_set1_sigalgs takes |num_values| ints and interprets them as pairs where
5050 // the first is the nid of a hash function and the second is an |EVP_PKEY_*|
5051 // value. It configures the signature algorithm preferences for |ssl| based on
5052 // them and returns one on success or zero on error.
5053 //
5054 // This API is compatible with OpenSSL. However, BoringSSL-specific code should
5055 // prefer |SSL_CTX_set_signing_algorithm_prefs| because it's clearer and it's
5056 // more convenient to codesearch for specific algorithm values.
5057 OPENSSL_EXPORT int SSL_set1_sigalgs(SSL *ssl, const int *values,
5058                                     size_t num_values);
5059 
5060 // SSL_CTX_set1_sigalgs_list takes a textual specification of a set of signature
5061 // algorithms and configures them on |ctx|. It returns one on success and zero
5062 // on error. See
5063 // https://www.openssl.org/docs/man1.1.0/man3/SSL_CTX_set1_sigalgs_list.html for
5064 // a description of the text format. Also note that TLS 1.3 names (e.g.
5065 // "rsa_pkcs1_md5_sha1") can also be used (as in OpenSSL, although OpenSSL
5066 // doesn't document that).
5067 //
5068 // This API is compatible with OpenSSL. However, BoringSSL-specific code should
5069 // prefer |SSL_CTX_set_signing_algorithm_prefs| because it's clearer and it's
5070 // more convenient to codesearch for specific algorithm values.
5071 OPENSSL_EXPORT int SSL_CTX_set1_sigalgs_list(SSL_CTX *ctx, const char *str);
5072 
5073 // SSL_set1_sigalgs_list takes a textual specification of a set of signature
5074 // algorithms and configures them on |ssl|. It returns one on success and zero
5075 // on error. See
5076 // https://www.openssl.org/docs/man1.1.0/man3/SSL_CTX_set1_sigalgs_list.html for
5077 // a description of the text format. Also note that TLS 1.3 names (e.g.
5078 // "rsa_pkcs1_md5_sha1") can also be used (as in OpenSSL, although OpenSSL
5079 // doesn't document that).
5080 //
5081 // This API is compatible with OpenSSL. However, BoringSSL-specific code should
5082 // prefer |SSL_CTX_set_signing_algorithm_prefs| because it's clearer and it's
5083 // more convenient to codesearch for specific algorithm values.
5084 OPENSSL_EXPORT int SSL_set1_sigalgs_list(SSL *ssl, const char *str);
5085 
5086 #define SSL_set_app_data(s, arg) (SSL_set_ex_data(s, 0, (char *)(arg)))
5087 #define SSL_get_app_data(s) (SSL_get_ex_data(s, 0))
5088 #define SSL_SESSION_set_app_data(s, a) \
5089   (SSL_SESSION_set_ex_data(s, 0, (char *)(a)))
5090 #define SSL_SESSION_get_app_data(s) (SSL_SESSION_get_ex_data(s, 0))
5091 #define SSL_CTX_get_app_data(ctx) (SSL_CTX_get_ex_data(ctx, 0))
5092 #define SSL_CTX_set_app_data(ctx, arg) \
5093   (SSL_CTX_set_ex_data(ctx, 0, (char *)(arg)))
5094 
5095 #define OpenSSL_add_ssl_algorithms() SSL_library_init()
5096 #define SSLeay_add_ssl_algorithms() SSL_library_init()
5097 
5098 #define SSL_get_cipher(ssl) SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
5099 #define SSL_get_cipher_bits(ssl, out_alg_bits) \
5100     SSL_CIPHER_get_bits(SSL_get_current_cipher(ssl), out_alg_bits)
5101 #define SSL_get_cipher_version(ssl) \
5102     SSL_CIPHER_get_version(SSL_get_current_cipher(ssl))
5103 #define SSL_get_cipher_name(ssl) \
5104     SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
5105 #define SSL_get_time(session) SSL_SESSION_get_time(session)
5106 #define SSL_set_time(session, time) SSL_SESSION_set_time((session), (time))
5107 #define SSL_get_timeout(session) SSL_SESSION_get_timeout(session)
5108 #define SSL_set_timeout(session, timeout) \
5109     SSL_SESSION_set_timeout((session), (timeout))
5110 
5111 struct ssl_comp_st {
5112   int id;
5113   const char *name;
5114   char *method;
5115 };
5116 
5117 DEFINE_STACK_OF(SSL_COMP)
5118 
5119 // The following flags do nothing and are included only to make it easier to
5120 // compile code with BoringSSL.
5121 #define SSL_MODE_AUTO_RETRY 0
5122 #define SSL_MODE_RELEASE_BUFFERS 0
5123 #define SSL_MODE_SEND_CLIENTHELLO_TIME 0
5124 #define SSL_MODE_SEND_SERVERHELLO_TIME 0
5125 #define SSL_OP_ALL 0
5126 #define SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0
5127 #define SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS 0
5128 #define SSL_OP_EPHEMERAL_RSA 0
5129 #define SSL_OP_LEGACY_SERVER_CONNECT 0
5130 #define SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER 0
5131 #define SSL_OP_MICROSOFT_SESS_ID_BUG 0
5132 #define SSL_OP_MSIE_SSLV2_RSA_PADDING 0
5133 #define SSL_OP_NETSCAPE_CA_DN_BUG 0
5134 #define SSL_OP_NETSCAPE_CHALLENGE_BUG 0
5135 #define SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG 0
5136 #define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0
5137 #define SSL_OP_NO_COMPRESSION 0
5138 #define SSL_OP_NO_RENEGOTIATION 0  // ssl_renegotiate_never is the default
5139 #define SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION 0
5140 #define SSL_OP_NO_SSLv2 0
5141 #define SSL_OP_NO_SSLv3 0
5142 #define SSL_OP_PKCS1_CHECK_1 0
5143 #define SSL_OP_PKCS1_CHECK_2 0
5144 #define SSL_OP_SINGLE_DH_USE 0
5145 #define SSL_OP_SINGLE_ECDH_USE 0
5146 #define SSL_OP_SSLEAY_080_CLIENT_DH_BUG 0
5147 #define SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG 0
5148 #define SSL_OP_TLS_BLOCK_PADDING_BUG 0
5149 #define SSL_OP_TLS_D5_BUG 0
5150 #define SSL_OP_TLS_ROLLBACK_BUG 0
5151 #define SSL_VERIFY_CLIENT_ONCE 0
5152 
5153 // SSL_cache_hit calls |SSL_session_reused|.
5154 OPENSSL_EXPORT int SSL_cache_hit(SSL *ssl);
5155 
5156 // SSL_get_default_timeout returns |SSL_DEFAULT_SESSION_TIMEOUT|.
5157 OPENSSL_EXPORT long SSL_get_default_timeout(const SSL *ssl);
5158 
5159 // SSL_get_version returns a string describing the TLS version used by |ssl|.
5160 // For example, "TLSv1.2" or "DTLSv1".
5161 OPENSSL_EXPORT const char *SSL_get_version(const SSL *ssl);
5162 
5163 // SSL_get_all_version_names outputs a list of possible strings
5164 // |SSL_get_version| may return in this version of BoringSSL. It writes at most
5165 // |max_out| entries to |out| and returns the total number it would have
5166 // written, if |max_out| had been large enough. |max_out| may be initially set
5167 // to zero to size the output.
5168 //
5169 // This function is only intended to help initialize tables in callers that want
5170 // possible strings pre-declared. This list would not be suitable to set a list
5171 // of supported features. It is in no particular order, and may contain
5172 // placeholder, experimental, or deprecated values that do not apply to every
5173 // caller. Future versions of BoringSSL may also return strings not in this
5174 // list, so this does not apply if, say, sending strings across services.
5175 OPENSSL_EXPORT size_t SSL_get_all_version_names(const char **out,
5176                                                 size_t max_out);
5177 
5178 // SSL_get_cipher_list returns the name of the |n|th cipher in the output of
5179 // |SSL_get_ciphers| or NULL if out of range. Use |SSL_get_ciphers| instead.
5180 OPENSSL_EXPORT const char *SSL_get_cipher_list(const SSL *ssl, int n);
5181 
5182 // SSL_CTX_set_client_cert_cb sets a callback which is called on the client if
5183 // the server requests a client certificate and none is configured. On success,
5184 // the callback should return one and set |*out_x509| to |*out_pkey| to a leaf
5185 // certificate and private key, respectively, passing ownership. It should
5186 // return zero to send no certificate and -1 to fail or pause the handshake. If
5187 // the handshake is paused, |SSL_get_error| will return
5188 // |SSL_ERROR_WANT_X509_LOOKUP|.
5189 //
5190 // The callback may call |SSL_get0_certificate_types| and
5191 // |SSL_get_client_CA_list| for information on the server's certificate request.
5192 //
5193 // Use |SSL_CTX_set_cert_cb| instead. Configuring intermediate certificates with
5194 // this function is confusing. This callback may not be registered concurrently
5195 // with |SSL_CTX_set_cert_cb| or |SSL_set_cert_cb|.
5196 OPENSSL_EXPORT void SSL_CTX_set_client_cert_cb(
5197     SSL_CTX *ctx, int (*cb)(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey));
5198 
5199 #define SSL_NOTHING SSL_ERROR_NONE
5200 #define SSL_WRITING SSL_ERROR_WANT_WRITE
5201 #define SSL_READING SSL_ERROR_WANT_READ
5202 
5203 // SSL_want returns one of the above values to determine what the most recent
5204 // operation on |ssl| was blocked on. Use |SSL_get_error| instead.
5205 OPENSSL_EXPORT int SSL_want(const SSL *ssl);
5206 
5207 #define SSL_want_read(ssl) (SSL_want(ssl) == SSL_READING)
5208 #define SSL_want_write(ssl) (SSL_want(ssl) == SSL_WRITING)
5209 
5210  // SSL_get_finished writes up to |count| bytes of the Finished message sent by
5211  // |ssl| to |buf|. It returns the total untruncated length or zero if none has
5212  // been sent yet. At TLS 1.3 and later, it returns zero.
5213  //
5214  // Use |SSL_get_tls_unique| instead.
5215 OPENSSL_EXPORT size_t SSL_get_finished(const SSL *ssl, void *buf, size_t count);
5216 
5217  // SSL_get_peer_finished writes up to |count| bytes of the Finished message
5218  // received from |ssl|'s peer to |buf|. It returns the total untruncated length
5219  // or zero if none has been received yet. At TLS 1.3 and later, it returns
5220  // zero.
5221  //
5222  // Use |SSL_get_tls_unique| instead.
5223 OPENSSL_EXPORT size_t SSL_get_peer_finished(const SSL *ssl, void *buf,
5224                                             size_t count);
5225 
5226 // SSL_alert_type_string returns "!". Use |SSL_alert_type_string_long|
5227 // instead.
5228 OPENSSL_EXPORT const char *SSL_alert_type_string(int value);
5229 
5230 // SSL_alert_desc_string returns "!!". Use |SSL_alert_desc_string_long|
5231 // instead.
5232 OPENSSL_EXPORT const char *SSL_alert_desc_string(int value);
5233 
5234 // SSL_state_string returns "!!!!!!". Use |SSL_state_string_long| for a more
5235 // intelligible string.
5236 OPENSSL_EXPORT const char *SSL_state_string(const SSL *ssl);
5237 
5238 // SSL_TXT_* expand to strings.
5239 #define SSL_TXT_MEDIUM "MEDIUM"
5240 #define SSL_TXT_HIGH "HIGH"
5241 #define SSL_TXT_FIPS "FIPS"
5242 #define SSL_TXT_kRSA "kRSA"
5243 #define SSL_TXT_kDHE "kDHE"
5244 #define SSL_TXT_kEDH "kEDH"
5245 #define SSL_TXT_kECDHE "kECDHE"
5246 #define SSL_TXT_kEECDH "kEECDH"
5247 #define SSL_TXT_kPSK "kPSK"
5248 #define SSL_TXT_aRSA "aRSA"
5249 #define SSL_TXT_aECDSA "aECDSA"
5250 #define SSL_TXT_aPSK "aPSK"
5251 #define SSL_TXT_DH "DH"
5252 #define SSL_TXT_DHE "DHE"
5253 #define SSL_TXT_EDH "EDH"
5254 #define SSL_TXT_RSA "RSA"
5255 #define SSL_TXT_ECDH "ECDH"
5256 #define SSL_TXT_ECDHE "ECDHE"
5257 #define SSL_TXT_EECDH "EECDH"
5258 #define SSL_TXT_ECDSA "ECDSA"
5259 #define SSL_TXT_PSK "PSK"
5260 #define SSL_TXT_3DES "3DES"
5261 #define SSL_TXT_RC4 "RC4"
5262 #define SSL_TXT_AES128 "AES128"
5263 #define SSL_TXT_AES256 "AES256"
5264 #define SSL_TXT_AES "AES"
5265 #define SSL_TXT_AES_GCM "AESGCM"
5266 #define SSL_TXT_CHACHA20 "CHACHA20"
5267 #define SSL_TXT_MD5 "MD5"
5268 #define SSL_TXT_SHA1 "SHA1"
5269 #define SSL_TXT_SHA "SHA"
5270 #define SSL_TXT_SHA256 "SHA256"
5271 #define SSL_TXT_SHA384 "SHA384"
5272 #define SSL_TXT_SSLV3 "SSLv3"
5273 #define SSL_TXT_TLSV1 "TLSv1"
5274 #define SSL_TXT_TLSV1_1 "TLSv1.1"
5275 #define SSL_TXT_TLSV1_2 "TLSv1.2"
5276 #define SSL_TXT_TLSV1_3 "TLSv1.3"
5277 #define SSL_TXT_ALL "ALL"
5278 #define SSL_TXT_CMPDEF "COMPLEMENTOFDEFAULT"
5279 
5280 typedef struct ssl_conf_ctx_st SSL_CONF_CTX;
5281 
5282 // SSL_state returns |SSL_ST_INIT| if a handshake is in progress and |SSL_ST_OK|
5283 // otherwise.
5284 //
5285 // Use |SSL_is_init| instead.
5286 OPENSSL_EXPORT int SSL_state(const SSL *ssl);
5287 
5288 #define SSL_get_state(ssl) SSL_state(ssl)
5289 
5290 // SSL_set_shutdown causes |ssl| to behave as if the shutdown bitmask (see
5291 // |SSL_get_shutdown|) were |mode|. This may be used to skip sending or
5292 // receiving close_notify in |SSL_shutdown| by causing the implementation to
5293 // believe the events already happened.
5294 //
5295 // It is an error to use |SSL_set_shutdown| to unset a bit that has already been
5296 // set. Doing so will trigger an |assert| in debug builds and otherwise be
5297 // ignored.
5298 //
5299 // Use |SSL_CTX_set_quiet_shutdown| instead.
5300 OPENSSL_EXPORT void SSL_set_shutdown(SSL *ssl, int mode);
5301 
5302 // SSL_CTX_set_tmp_ecdh calls |SSL_CTX_set1_groups| with a one-element list
5303 // containing |ec_key|'s curve. The remainder of |ec_key| is ignored.
5304 OPENSSL_EXPORT int SSL_CTX_set_tmp_ecdh(SSL_CTX *ctx, const EC_KEY *ec_key);
5305 
5306 // SSL_set_tmp_ecdh calls |SSL_set1_groups| with a one-element list containing
5307 // |ec_key|'s curve. The remainder of |ec_key| is ignored.
5308 OPENSSL_EXPORT int SSL_set_tmp_ecdh(SSL *ssl, const EC_KEY *ec_key);
5309 
5310 #if !defined(OPENSSL_NO_FILESYSTEM)
5311 // SSL_add_dir_cert_subjects_to_stack lists files in directory |dir|. It calls
5312 // |SSL_add_file_cert_subjects_to_stack| on each file and returns one on success
5313 // or zero on error. This function is only available from the libdecrepit
5314 // library.
5315 OPENSSL_EXPORT int SSL_add_dir_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
5316                                                       const char *dir);
5317 #endif
5318 
5319 // SSL_CTX_enable_tls_channel_id calls |SSL_CTX_set_tls_channel_id_enabled|.
5320 OPENSSL_EXPORT int SSL_CTX_enable_tls_channel_id(SSL_CTX *ctx);
5321 
5322 // SSL_enable_tls_channel_id calls |SSL_set_tls_channel_id_enabled|.
5323 OPENSSL_EXPORT int SSL_enable_tls_channel_id(SSL *ssl);
5324 
5325 // BIO_f_ssl returns a |BIO_METHOD| that can wrap an |SSL*| in a |BIO*|. Note
5326 // that this has quite different behaviour from the version in OpenSSL (notably
5327 // that it doesn't try to auto renegotiate).
5328 //
5329 // IMPORTANT: if you are not curl, don't use this.
5330 OPENSSL_EXPORT const BIO_METHOD *BIO_f_ssl(void);
5331 
5332 // BIO_set_ssl sets |ssl| as the underlying connection for |bio|, which must
5333 // have been created using |BIO_f_ssl|. If |take_owership| is true, |bio| will
5334 // call |SSL_free| on |ssl| when closed. It returns one on success or something
5335 // other than one on error.
5336 OPENSSL_EXPORT long BIO_set_ssl(BIO *bio, SSL *ssl, int take_owership);
5337 
5338 // SSL_CTX_set_ecdh_auto returns one.
5339 #define SSL_CTX_set_ecdh_auto(ctx, onoff) 1
5340 
5341 // SSL_set_ecdh_auto returns one.
5342 #define SSL_set_ecdh_auto(ssl, onoff) 1
5343 
5344 // SSL_get_session returns a non-owning pointer to |ssl|'s session. For
5345 // historical reasons, which session it returns depends on |ssl|'s state.
5346 //
5347 // Prior to the start of the initial handshake, it returns the session the
5348 // caller set with |SSL_set_session|. After the initial handshake has finished
5349 // and if no additional handshakes are in progress, it returns the currently
5350 // active session. Its behavior is undefined while a handshake is in progress.
5351 //
5352 // If trying to add new sessions to an external session cache, use
5353 // |SSL_CTX_sess_set_new_cb| instead. In particular, using the callback is
5354 // required as of TLS 1.3. For compatibility, this function will return an
5355 // unresumable session which may be cached, but will never be resumed.
5356 //
5357 // If querying properties of the connection, use APIs on the |SSL| object.
5358 OPENSSL_EXPORT SSL_SESSION *SSL_get_session(const SSL *ssl);
5359 
5360 // SSL_get0_session is an alias for |SSL_get_session|.
5361 #define SSL_get0_session SSL_get_session
5362 
5363 // SSL_get1_session acts like |SSL_get_session| but returns a new reference to
5364 // the session.
5365 OPENSSL_EXPORT SSL_SESSION *SSL_get1_session(SSL *ssl);
5366 
5367 #define OPENSSL_INIT_NO_LOAD_SSL_STRINGS 0
5368 #define OPENSSL_INIT_LOAD_SSL_STRINGS 0
5369 #define OPENSSL_INIT_SSL_DEFAULT 0
5370 
5371 // OPENSSL_init_ssl calls |CRYPTO_library_init| and returns one.
5372 OPENSSL_EXPORT int OPENSSL_init_ssl(uint64_t opts,
5373                                     const OPENSSL_INIT_SETTINGS *settings);
5374 
5375 // The following constants are legacy aliases for RSA-PSS with rsaEncryption
5376 // keys. Use the new names instead.
5377 #define SSL_SIGN_RSA_PSS_SHA256 SSL_SIGN_RSA_PSS_RSAE_SHA256
5378 #define SSL_SIGN_RSA_PSS_SHA384 SSL_SIGN_RSA_PSS_RSAE_SHA384
5379 #define SSL_SIGN_RSA_PSS_SHA512 SSL_SIGN_RSA_PSS_RSAE_SHA512
5380 
5381 // SSL_set_tlsext_status_type configures a client to request OCSP stapling if
5382 // |type| is |TLSEXT_STATUSTYPE_ocsp| and disables it otherwise. It returns one
5383 // on success and zero if handshake configuration has already been shed.
5384 //
5385 // Use |SSL_enable_ocsp_stapling| instead.
5386 OPENSSL_EXPORT int SSL_set_tlsext_status_type(SSL *ssl, int type);
5387 
5388 // SSL_get_tlsext_status_type returns |TLSEXT_STATUSTYPE_ocsp| if the client
5389 // requested OCSP stapling and |TLSEXT_STATUSTYPE_nothing| otherwise. On the
5390 // client, this reflects whether OCSP stapling was enabled via, e.g.,
5391 // |SSL_set_tlsext_status_type|. On the server, this is determined during the
5392 // handshake. It may be queried in callbacks set by |SSL_CTX_set_cert_cb|. The
5393 // result is undefined after the handshake completes.
5394 OPENSSL_EXPORT int SSL_get_tlsext_status_type(const SSL *ssl);
5395 
5396 // SSL_set_tlsext_status_ocsp_resp sets the OCSP response. It returns one on
5397 // success and zero on error. On success, |ssl| takes ownership of |resp|, which
5398 // must have been allocated by |OPENSSL_malloc|.
5399 //
5400 // Use |SSL_set_ocsp_response| instead.
5401 OPENSSL_EXPORT int SSL_set_tlsext_status_ocsp_resp(SSL *ssl, uint8_t *resp,
5402                                                    size_t resp_len);
5403 
5404 // SSL_get_tlsext_status_ocsp_resp sets |*out| to point to the OCSP response
5405 // from the server. It returns the length of the response. If there was no
5406 // response, it sets |*out| to NULL and returns zero.
5407 //
5408 // Use |SSL_get0_ocsp_response| instead.
5409 //
5410 // WARNING: the returned data is not guaranteed to be well formed.
5411 OPENSSL_EXPORT size_t SSL_get_tlsext_status_ocsp_resp(const SSL *ssl,
5412                                                       const uint8_t **out);
5413 
5414 // SSL_CTX_set_tlsext_status_cb configures the legacy OpenSSL OCSP callback and
5415 // returns one. Though the type signature is the same, this callback has
5416 // different behavior for client and server connections:
5417 //
5418 // For clients, the callback is called after certificate verification. It should
5419 // return one for success, zero for a bad OCSP response, and a negative number
5420 // for internal error. Instead, handle this as part of certificate verification.
5421 // (Historically, OpenSSL verified certificates just before parsing stapled OCSP
5422 // responses, but BoringSSL fixes this ordering. All server credentials are
5423 // available during verification.)
5424 //
5425 // Do not use this callback as a server. It is provided for compatibility
5426 // purposes only. For servers, it is called to configure server credentials. It
5427 // should return |SSL_TLSEXT_ERR_OK| on success, |SSL_TLSEXT_ERR_NOACK| to
5428 // ignore OCSP requests, or |SSL_TLSEXT_ERR_ALERT_FATAL| on error. It is usually
5429 // used to fetch OCSP responses on demand, which is not ideal. Instead, treat
5430 // OCSP responses like other server credentials, such as certificates or SCT
5431 // lists. Configure, store, and refresh them eagerly. This avoids downtime if
5432 // the CA's OCSP responder is briefly offline.
5433 OPENSSL_EXPORT int SSL_CTX_set_tlsext_status_cb(SSL_CTX *ctx,
5434                                                 int (*callback)(SSL *ssl,
5435                                                                 void *arg));
5436 
5437 // SSL_CTX_set_tlsext_status_arg sets additional data for
5438 // |SSL_CTX_set_tlsext_status_cb|'s callback and returns one.
5439 OPENSSL_EXPORT int SSL_CTX_set_tlsext_status_arg(SSL_CTX *ctx, void *arg);
5440 
5441 // The following symbols are compatibility aliases for reason codes used when
5442 // receiving an alert from the peer. Use the other names instead, which fit the
5443 // naming convention.
5444 //
5445 // TODO(davidben): Fix references to |SSL_R_TLSV1_CERTIFICATE_REQUIRED| and
5446 // remove the compatibility value. The others come from OpenSSL.
5447 #define SSL_R_TLSV1_UNSUPPORTED_EXTENSION \
5448   SSL_R_TLSV1_ALERT_UNSUPPORTED_EXTENSION
5449 #define SSL_R_TLSV1_CERTIFICATE_UNOBTAINABLE \
5450   SSL_R_TLSV1_ALERT_CERTIFICATE_UNOBTAINABLE
5451 #define SSL_R_TLSV1_UNRECOGNIZED_NAME SSL_R_TLSV1_ALERT_UNRECOGNIZED_NAME
5452 #define SSL_R_TLSV1_BAD_CERTIFICATE_STATUS_RESPONSE \
5453   SSL_R_TLSV1_ALERT_BAD_CERTIFICATE_STATUS_RESPONSE
5454 #define SSL_R_TLSV1_BAD_CERTIFICATE_HASH_VALUE \
5455   SSL_R_TLSV1_ALERT_BAD_CERTIFICATE_HASH_VALUE
5456 #define SSL_R_TLSV1_CERTIFICATE_REQUIRED SSL_R_TLSV1_ALERT_CERTIFICATE_REQUIRED
5457 
5458 // The following symbols are compatibility aliases for |SSL_GROUP_*|.
5459 #define SSL_CURVE_SECP224R1 SSL_GROUP_SECP224R1
5460 #define SSL_CURVE_SECP256R1 SSL_GROUP_SECP256R1
5461 #define SSL_CURVE_SECP384R1 SSL_GROUP_SECP384R1
5462 #define SSL_CURVE_SECP521R1 SSL_GROUP_SECP521R1
5463 #define SSL_CURVE_X25519 SSL_GROUP_X25519
5464 #define SSL_CURVE_X25519_KYBER768_DRAFT00 SSL_GROUP_X25519_KYBER768_DRAFT00
5465 
5466 // SSL_get_curve_id calls |SSL_get_group_id|.
5467 OPENSSL_EXPORT uint16_t SSL_get_curve_id(const SSL *ssl);
5468 
5469 // SSL_get_curve_name calls |SSL_get_group_name|.
5470 OPENSSL_EXPORT const char *SSL_get_curve_name(uint16_t curve_id);
5471 
5472 // SSL_get_all_curve_names calls |SSL_get_all_group_names|.
5473 OPENSSL_EXPORT size_t SSL_get_all_curve_names(const char **out, size_t max_out);
5474 
5475 // SSL_CTX_set1_curves calls |SSL_CTX_set1_groups|.
5476 OPENSSL_EXPORT int SSL_CTX_set1_curves(SSL_CTX *ctx, const int *curves,
5477                                        size_t num_curves);
5478 
5479 // SSL_set1_curves calls |SSL_set1_groups|.
5480 OPENSSL_EXPORT int SSL_set1_curves(SSL *ssl, const int *curves,
5481                                    size_t num_curves);
5482 
5483 // SSL_CTX_set1_curves_list calls |SSL_CTX_set1_groups_list|.
5484 OPENSSL_EXPORT int SSL_CTX_set1_curves_list(SSL_CTX *ctx, const char *curves);
5485 
5486 // SSL_set1_curves_list calls |SSL_set1_groups_list|.
5487 OPENSSL_EXPORT int SSL_set1_curves_list(SSL *ssl, const char *curves);
5488 
5489 // TLSEXT_nid_unknown is a constant used in OpenSSL for
5490 // |SSL_get_negotiated_group| to return an unrecognized group. BoringSSL never
5491 // returns this value, but we define this constant for compatibility.
5492 #define TLSEXT_nid_unknown 0x1000000
5493 
5494 // SSL_CTX_check_private_key returns one if |ctx| has both a certificate and
5495 // private key, and zero otherwise.
5496 //
5497 // This function does not check consistency because the library checks when the
5498 // certificate and key are individually configured. However, if the private key
5499 // is configured before the certificate, inconsistent private keys are silently
5500 // dropped. Some callers are inadvertently relying on this function to detect
5501 // when this happens.
5502 //
5503 // Instead, callers should configure the certificate first, then the private
5504 // key, checking for errors in each. This function is then unnecessary.
5505 OPENSSL_EXPORT int SSL_CTX_check_private_key(const SSL_CTX *ctx);
5506 
5507 // SSL_check_private_key returns one if |ssl| has both a certificate and private
5508 // key, and zero otherwise.
5509 //
5510 // See discussion in |SSL_CTX_check_private_key|.
5511 OPENSSL_EXPORT int SSL_check_private_key(const SSL *ssl);
5512 
5513 
5514 // Compliance policy configurations
5515 //
5516 // A TLS connection has a large number of different parameters. Some are well
5517 // known, like cipher suites, but many are obscure and configuration functions
5518 // for them may not exist. These policy controls allow broad configuration
5519 // goals to be specified so that they can flow down to all the different
5520 // parameters of a TLS connection.
5521 
5522 enum ssl_compliance_policy_t BORINGSSL_ENUM_INT {
5523   // ssl_compliance_policy_none does nothing. However, since setting this
5524   // doesn't undo other policies it's an error to try and set it.
5525   ssl_compliance_policy_none,
5526 
5527   // ssl_compliance_policy_fips_202205 configures a TLS connection to use:
5528   //   * TLS 1.2 or 1.3
5529   //   * For TLS 1.2, only ECDHE_[RSA|ECDSA]_WITH_AES_*_GCM_SHA*.
5530   //   * For TLS 1.3, only AES-GCM
5531   //   * P-256 or P-384 for key agreement.
5532   //   * For server signatures, only PKCS#1/PSS with SHA256/384/512, or ECDSA
5533   //     with P-256 or P-384.
5534   //
5535   // Note: this policy can be configured even if BoringSSL has not been built in
5536   // FIPS mode. Call |FIPS_mode| to check that.
5537   //
5538   // Note: this setting aids with compliance with NIST requirements but does not
5539   // guarantee it. Careful reading of SP 800-52r2 is recommended.
5540   ssl_compliance_policy_fips_202205,
5541 
5542   // ssl_compliance_policy_wpa3_192_202304 configures a TLS connection to use:
5543   //   * TLS 1.2 or 1.3.
5544   //   * For TLS 1.2, only TLS_ECDHE_[ECDSA|RSA]_WITH_AES_256_GCM_SHA384.
5545   //   * For TLS 1.3, only AES-256-GCM.
5546   //   * P-384 for key agreement.
5547   //   * For handshake signatures, only ECDSA with P-384 and SHA-384, or RSA
5548   //     with SHA-384 or SHA-512.
5549   //
5550   // No limitations on the certificate chain nor leaf public key are imposed,
5551   // other than by the supported signature algorithms. But WPA3's "192-bit"
5552   // mode requires at least P-384 or 3072-bit along the chain. The caller must
5553   // enforce this themselves on the verified chain using functions such as
5554   // `X509_STORE_CTX_get0_chain`.
5555   //
5556   // Note that this setting is less secure than the default. The
5557   // implementation risks of using a more obscure primitive like P-384
5558   // dominate other considerations.
5559   ssl_compliance_policy_wpa3_192_202304,
5560 };
5561 
5562 // SSL_CTX_set_compliance_policy configures various aspects of |ctx| based on
5563 // the given policy requirements. Subsequently calling other functions that
5564 // configure |ctx| may override |policy|, or may not. This should be the final
5565 // configuration function called in order to have defined behaviour. It's a
5566 // fatal error if |policy| is |ssl_compliance_policy_none|.
5567 OPENSSL_EXPORT int SSL_CTX_set_compliance_policy(
5568     SSL_CTX *ctx, enum ssl_compliance_policy_t policy);
5569 
5570 // SSL_set_compliance_policy acts the same as |SSL_CTX_set_compliance_policy|,
5571 // but only configures a single |SSL*|.
5572 OPENSSL_EXPORT int SSL_set_compliance_policy(
5573     SSL *ssl, enum ssl_compliance_policy_t policy);
5574 
5575 
5576 // Nodejs compatibility section (hidden).
5577 //
5578 // These defines exist for node.js, with the hope that we can eliminate the
5579 // need for them over time.
5580 
5581 #define SSLerr(function, reason) \
5582   ERR_put_error(ERR_LIB_SSL, 0, reason, __FILE__, __LINE__)
5583 
5584 
5585 // Preprocessor compatibility section (hidden).
5586 //
5587 // Historically, a number of APIs were implemented in OpenSSL as macros and
5588 // constants to 'ctrl' functions. To avoid breaking #ifdefs in consumers, this
5589 // section defines a number of legacy macros.
5590 //
5591 // Although using either the CTRL values or their wrapper macros in #ifdefs is
5592 // still supported, the CTRL values may not be passed to |SSL_ctrl| and
5593 // |SSL_CTX_ctrl|. Call the functions (previously wrapper macros) instead.
5594 //
5595 // See PORTING.md in the BoringSSL source tree for a table of corresponding
5596 // functions.
5597 // https://boringssl.googlesource.com/boringssl/+/master/PORTING.md#Replacements-for-values
5598 
5599 #define DTLS_CTRL_GET_TIMEOUT doesnt_exist
5600 #define DTLS_CTRL_HANDLE_TIMEOUT doesnt_exist
5601 #define SSL_CTRL_CHAIN doesnt_exist
5602 #define SSL_CTRL_CHAIN_CERT doesnt_exist
5603 #define SSL_CTRL_CHANNEL_ID doesnt_exist
5604 #define SSL_CTRL_CLEAR_EXTRA_CHAIN_CERTS doesnt_exist
5605 #define SSL_CTRL_CLEAR_MODE doesnt_exist
5606 #define SSL_CTRL_CLEAR_OPTIONS doesnt_exist
5607 #define SSL_CTRL_EXTRA_CHAIN_CERT doesnt_exist
5608 #define SSL_CTRL_GET_CHAIN_CERTS doesnt_exist
5609 #define SSL_CTRL_GET_CHANNEL_ID doesnt_exist
5610 #define SSL_CTRL_GET_CLIENT_CERT_TYPES doesnt_exist
5611 #define SSL_CTRL_GET_EXTRA_CHAIN_CERTS doesnt_exist
5612 #define SSL_CTRL_GET_MAX_CERT_LIST doesnt_exist
5613 #define SSL_CTRL_GET_NEGOTIATED_GROUP doesnt_exist
5614 #define SSL_CTRL_GET_NUM_RENEGOTIATIONS doesnt_exist
5615 #define SSL_CTRL_GET_READ_AHEAD doesnt_exist
5616 #define SSL_CTRL_GET_RI_SUPPORT doesnt_exist
5617 #define SSL_CTRL_GET_SERVER_TMP_KEY doesnt_exist
5618 #define SSL_CTRL_GET_SESSION_REUSED doesnt_exist
5619 #define SSL_CTRL_GET_SESS_CACHE_MODE doesnt_exist
5620 #define SSL_CTRL_GET_SESS_CACHE_SIZE doesnt_exist
5621 #define SSL_CTRL_GET_TLSEXT_TICKET_KEYS doesnt_exist
5622 #define SSL_CTRL_GET_TOTAL_RENEGOTIATIONS doesnt_exist
5623 #define SSL_CTRL_MODE doesnt_exist
5624 #define SSL_CTRL_NEED_TMP_RSA doesnt_exist
5625 #define SSL_CTRL_OPTIONS doesnt_exist
5626 #define SSL_CTRL_SESS_NUMBER doesnt_exist
5627 #define SSL_CTRL_SET_CURVES doesnt_exist
5628 #define SSL_CTRL_SET_CURVES_LIST doesnt_exist
5629 #define SSL_CTRL_SET_GROUPS doesnt_exist
5630 #define SSL_CTRL_SET_GROUPS_LIST doesnt_exist
5631 #define SSL_CTRL_SET_ECDH_AUTO doesnt_exist
5632 #define SSL_CTRL_SET_MAX_CERT_LIST doesnt_exist
5633 #define SSL_CTRL_SET_MAX_SEND_FRAGMENT doesnt_exist
5634 #define SSL_CTRL_SET_MSG_CALLBACK doesnt_exist
5635 #define SSL_CTRL_SET_MSG_CALLBACK_ARG doesnt_exist
5636 #define SSL_CTRL_SET_MTU doesnt_exist
5637 #define SSL_CTRL_SET_READ_AHEAD doesnt_exist
5638 #define SSL_CTRL_SET_SESS_CACHE_MODE doesnt_exist
5639 #define SSL_CTRL_SET_SESS_CACHE_SIZE doesnt_exist
5640 #define SSL_CTRL_SET_TLSEXT_HOSTNAME doesnt_exist
5641 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG doesnt_exist
5642 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_CB doesnt_exist
5643 #define SSL_CTRL_SET_TLSEXT_TICKET_KEYS doesnt_exist
5644 #define SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB doesnt_exist
5645 #define SSL_CTRL_SET_TMP_DH doesnt_exist
5646 #define SSL_CTRL_SET_TMP_DH_CB doesnt_exist
5647 #define SSL_CTRL_SET_TMP_ECDH doesnt_exist
5648 #define SSL_CTRL_SET_TMP_ECDH_CB doesnt_exist
5649 #define SSL_CTRL_SET_TMP_RSA doesnt_exist
5650 #define SSL_CTRL_SET_TMP_RSA_CB doesnt_exist
5651 
5652 // |BORINGSSL_PREFIX| already makes each of these symbols into macros, so there
5653 // is no need to define conflicting macros.
5654 #if !defined(BORINGSSL_PREFIX)
5655 
5656 #define DTLSv1_get_timeout DTLSv1_get_timeout
5657 #define DTLSv1_handle_timeout DTLSv1_handle_timeout
5658 #define SSL_CTX_add0_chain_cert SSL_CTX_add0_chain_cert
5659 #define SSL_CTX_add1_chain_cert SSL_CTX_add1_chain_cert
5660 #define SSL_CTX_add_extra_chain_cert SSL_CTX_add_extra_chain_cert
5661 #define SSL_CTX_clear_extra_chain_certs SSL_CTX_clear_extra_chain_certs
5662 #define SSL_CTX_clear_chain_certs SSL_CTX_clear_chain_certs
5663 #define SSL_CTX_clear_mode SSL_CTX_clear_mode
5664 #define SSL_CTX_clear_options SSL_CTX_clear_options
5665 #define SSL_CTX_get0_chain_certs SSL_CTX_get0_chain_certs
5666 #define SSL_CTX_get_extra_chain_certs SSL_CTX_get_extra_chain_certs
5667 #define SSL_CTX_get_max_cert_list SSL_CTX_get_max_cert_list
5668 #define SSL_CTX_get_mode SSL_CTX_get_mode
5669 #define SSL_CTX_get_options SSL_CTX_get_options
5670 #define SSL_CTX_get_read_ahead SSL_CTX_get_read_ahead
5671 #define SSL_CTX_get_session_cache_mode SSL_CTX_get_session_cache_mode
5672 #define SSL_CTX_get_tlsext_ticket_keys SSL_CTX_get_tlsext_ticket_keys
5673 #define SSL_CTX_need_tmp_RSA SSL_CTX_need_tmp_RSA
5674 #define SSL_CTX_sess_get_cache_size SSL_CTX_sess_get_cache_size
5675 #define SSL_CTX_sess_number SSL_CTX_sess_number
5676 #define SSL_CTX_sess_set_cache_size SSL_CTX_sess_set_cache_size
5677 #define SSL_CTX_set0_chain SSL_CTX_set0_chain
5678 #define SSL_CTX_set1_chain SSL_CTX_set1_chain
5679 #define SSL_CTX_set1_curves SSL_CTX_set1_curves
5680 #define SSL_CTX_set1_groups SSL_CTX_set1_groups
5681 #define SSL_CTX_set_max_cert_list SSL_CTX_set_max_cert_list
5682 #define SSL_CTX_set_max_send_fragment SSL_CTX_set_max_send_fragment
5683 #define SSL_CTX_set_mode SSL_CTX_set_mode
5684 #define SSL_CTX_set_msg_callback_arg SSL_CTX_set_msg_callback_arg
5685 #define SSL_CTX_set_options SSL_CTX_set_options
5686 #define SSL_CTX_set_read_ahead SSL_CTX_set_read_ahead
5687 #define SSL_CTX_set_session_cache_mode SSL_CTX_set_session_cache_mode
5688 #define SSL_CTX_set_tlsext_servername_arg SSL_CTX_set_tlsext_servername_arg
5689 #define SSL_CTX_set_tlsext_servername_callback \
5690     SSL_CTX_set_tlsext_servername_callback
5691 #define SSL_CTX_set_tlsext_ticket_key_cb SSL_CTX_set_tlsext_ticket_key_cb
5692 #define SSL_CTX_set_tlsext_ticket_keys SSL_CTX_set_tlsext_ticket_keys
5693 #define SSL_CTX_set_tmp_dh SSL_CTX_set_tmp_dh
5694 #define SSL_CTX_set_tmp_ecdh SSL_CTX_set_tmp_ecdh
5695 #define SSL_CTX_set_tmp_rsa SSL_CTX_set_tmp_rsa
5696 #define SSL_add0_chain_cert SSL_add0_chain_cert
5697 #define SSL_add1_chain_cert SSL_add1_chain_cert
5698 #define SSL_clear_chain_certs SSL_clear_chain_certs
5699 #define SSL_clear_mode SSL_clear_mode
5700 #define SSL_clear_options SSL_clear_options
5701 #define SSL_get0_certificate_types SSL_get0_certificate_types
5702 #define SSL_get0_chain_certs SSL_get0_chain_certs
5703 #define SSL_get_max_cert_list SSL_get_max_cert_list
5704 #define SSL_get_mode SSL_get_mode
5705 #define SSL_get_negotiated_group SSL_get_negotiated_group
5706 #define SSL_get_options SSL_get_options
5707 #define SSL_get_secure_renegotiation_support \
5708     SSL_get_secure_renegotiation_support
5709 #define SSL_need_tmp_RSA SSL_need_tmp_RSA
5710 #define SSL_num_renegotiations SSL_num_renegotiations
5711 #define SSL_session_reused SSL_session_reused
5712 #define SSL_set0_chain SSL_set0_chain
5713 #define SSL_set1_chain SSL_set1_chain
5714 #define SSL_set1_curves SSL_set1_curves
5715 #define SSL_set1_groups SSL_set1_groups
5716 #define SSL_set_max_cert_list SSL_set_max_cert_list
5717 #define SSL_set_max_send_fragment SSL_set_max_send_fragment
5718 #define SSL_set_mode SSL_set_mode
5719 #define SSL_set_msg_callback_arg SSL_set_msg_callback_arg
5720 #define SSL_set_mtu SSL_set_mtu
5721 #define SSL_set_options SSL_set_options
5722 #define SSL_set_tlsext_host_name SSL_set_tlsext_host_name
5723 #define SSL_set_tmp_dh SSL_set_tmp_dh
5724 #define SSL_set_tmp_ecdh SSL_set_tmp_ecdh
5725 #define SSL_set_tmp_rsa SSL_set_tmp_rsa
5726 #define SSL_total_renegotiations SSL_total_renegotiations
5727 
5728 #endif // !defined(BORINGSSL_PREFIX)
5729 
5730 
5731 #if defined(__cplusplus)
5732 }  // extern C
5733 
5734 #if !defined(BORINGSSL_NO_CXX)
5735 
5736 extern "C++" {
5737 
5738 BSSL_NAMESPACE_BEGIN
5739 
5740 BORINGSSL_MAKE_DELETER(SSL, SSL_free)
5741 BORINGSSL_MAKE_DELETER(SSL_CREDENTIAL, SSL_CREDENTIAL_free)
5742 BORINGSSL_MAKE_UP_REF(SSL_CREDENTIAL, SSL_CREDENTIAL_up_ref)
5743 BORINGSSL_MAKE_DELETER(SSL_CTX, SSL_CTX_free)
5744 BORINGSSL_MAKE_UP_REF(SSL_CTX, SSL_CTX_up_ref)
5745 BORINGSSL_MAKE_DELETER(SSL_ECH_KEYS, SSL_ECH_KEYS_free)
5746 BORINGSSL_MAKE_UP_REF(SSL_ECH_KEYS, SSL_ECH_KEYS_up_ref)
5747 BORINGSSL_MAKE_DELETER(SSL_SESSION, SSL_SESSION_free)
5748 BORINGSSL_MAKE_UP_REF(SSL_SESSION, SSL_SESSION_up_ref)
5749 
5750 
5751 // *** DEPRECATED EXPERIMENT — DO NOT USE ***
5752 //
5753 // Split handshakes.
5754 //
5755 // WARNING: This mechanism is deprecated and should not be used. It is very
5756 // fragile and difficult to use correctly. The relationship between
5757 // configuration options across the two halves is ill-defined and not
5758 // self-consistent. Additionally, version skew across the two halves risks
5759 // unusual behavior and connection failure. New development should use the
5760 // handshake hints API. Existing deployments should migrate to handshake hints
5761 // to reduce the risk of service outages.
5762 //
5763 // Split handshakes allows the handshake part of a TLS connection to be
5764 // performed in a different process (or on a different machine) than the data
5765 // exchange. This only applies to servers.
5766 //
5767 // In the first part of a split handshake, an |SSL| (where the |SSL_CTX| has
5768 // been configured with |SSL_CTX_set_handoff_mode|) is used normally. Once the
5769 // ClientHello message has been received, the handshake will stop and
5770 // |SSL_get_error| will indicate |SSL_ERROR_HANDOFF|. At this point (and only
5771 // at this point), |SSL_serialize_handoff| can be called to write the “handoff”
5772 // state of the connection.
5773 //
5774 // Elsewhere, a fresh |SSL| can be used with |SSL_apply_handoff| to continue
5775 // the connection. The connection from the client is fed into this |SSL|, and
5776 // the handshake resumed. When the handshake stops again and |SSL_get_error|
5777 // indicates |SSL_ERROR_HANDBACK|, |SSL_serialize_handback| should be called to
5778 // serialize the state of the handshake again.
5779 //
5780 // Back at the first location, a fresh |SSL| can be used with
5781 // |SSL_apply_handback|. Then the client's connection can be processed mostly
5782 // as normal.
5783 //
5784 // Lastly, when a connection is in the handoff state, whether or not
5785 // |SSL_serialize_handoff| is called, |SSL_decline_handoff| will move it back
5786 // into a normal state where the connection can proceed without impact.
5787 //
5788 // WARNING: Currently only works with TLS 1.0–1.2.
5789 // WARNING: The serialisation formats are not yet stable: version skew may be
5790 //     fatal.
5791 // WARNING: The handback data contains sensitive key material and must be
5792 //     protected.
5793 // WARNING: Some calls on the final |SSL| will not work. Just as an example,
5794 //     calls like |SSL_get0_session_id_context| and |SSL_get_privatekey| won't
5795 //     work because the certificate used for handshaking isn't available.
5796 // WARNING: |SSL_apply_handoff| may trigger “msg” callback calls.
5797 
5798 OPENSSL_EXPORT void SSL_CTX_set_handoff_mode(SSL_CTX *ctx, bool on);
5799 OPENSSL_EXPORT void SSL_set_handoff_mode(SSL *SSL, bool on);
5800 OPENSSL_EXPORT bool SSL_serialize_handoff(const SSL *ssl, CBB *out,
5801                                           SSL_CLIENT_HELLO *out_hello);
5802 OPENSSL_EXPORT bool SSL_decline_handoff(SSL *ssl);
5803 OPENSSL_EXPORT bool SSL_apply_handoff(SSL *ssl, Span<const uint8_t> handoff);
5804 OPENSSL_EXPORT bool SSL_serialize_handback(const SSL *ssl, CBB *out);
5805 OPENSSL_EXPORT bool SSL_apply_handback(SSL *ssl, Span<const uint8_t> handback);
5806 
5807 // SSL_get_traffic_secrets sets |*out_read_traffic_secret| and
5808 // |*out_write_traffic_secret| to reference the TLS 1.3 traffic secrets for
5809 // |ssl|. This function is only valid on TLS 1.3 connections that have
5810 // completed the handshake. It returns true on success and false on error.
5811 OPENSSL_EXPORT bool SSL_get_traffic_secrets(
5812     const SSL *ssl, Span<const uint8_t> *out_read_traffic_secret,
5813     Span<const uint8_t> *out_write_traffic_secret);
5814 
5815 // SSL_CTX_set_aes_hw_override_for_testing sets |override_value| to
5816 // override checking for aes hardware support for testing. If |override_value|
5817 // is set to true, the library will behave as if aes hardware support is
5818 // present. If it is set to false, the library will behave as if aes hardware
5819 // support is not present.
5820 OPENSSL_EXPORT void SSL_CTX_set_aes_hw_override_for_testing(
5821     SSL_CTX *ctx, bool override_value);
5822 
5823 // SSL_set_aes_hw_override_for_testing acts the same as
5824 // |SSL_CTX_set_aes_override_for_testing| but only configures a single |SSL*|.
5825 OPENSSL_EXPORT void SSL_set_aes_hw_override_for_testing(SSL *ssl,
5826                                                         bool override_value);
5827 
5828 BSSL_NAMESPACE_END
5829 
5830 }  // extern C++
5831 
5832 #endif  // !defined(BORINGSSL_NO_CXX)
5833 
5834 #endif
5835 
5836 #define SSL_R_APP_DATA_IN_HANDSHAKE 100
5837 #define SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT 101
5838 #define SSL_R_BAD_ALERT 102
5839 #define SSL_R_BAD_CHANGE_CIPHER_SPEC 103
5840 #define SSL_R_BAD_DATA_RETURNED_BY_CALLBACK 104
5841 #define SSL_R_BAD_DH_P_LENGTH 105
5842 #define SSL_R_BAD_DIGEST_LENGTH 106
5843 #define SSL_R_BAD_ECC_CERT 107
5844 #define SSL_R_BAD_ECPOINT 108
5845 #define SSL_R_BAD_HANDSHAKE_RECORD 109
5846 #define SSL_R_BAD_HELLO_REQUEST 110
5847 #define SSL_R_BAD_LENGTH 111
5848 #define SSL_R_BAD_PACKET_LENGTH 112
5849 #define SSL_R_BAD_RSA_ENCRYPT 113
5850 #define SSL_R_BAD_SIGNATURE 114
5851 #define SSL_R_BAD_SRTP_MKI_VALUE 115
5852 #define SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST 116
5853 #define SSL_R_BAD_SSL_FILETYPE 117
5854 #define SSL_R_BAD_WRITE_RETRY 118
5855 #define SSL_R_BIO_NOT_SET 119
5856 #define SSL_R_BN_LIB 120
5857 #define SSL_R_BUFFER_TOO_SMALL 121
5858 #define SSL_R_CA_DN_LENGTH_MISMATCH 122
5859 #define SSL_R_CA_DN_TOO_LONG 123
5860 #define SSL_R_CCS_RECEIVED_EARLY 124
5861 #define SSL_R_CERTIFICATE_VERIFY_FAILED 125
5862 #define SSL_R_CERT_CB_ERROR 126
5863 #define SSL_R_CERT_LENGTH_MISMATCH 127
5864 #define SSL_R_CHANNEL_ID_NOT_P256 128
5865 #define SSL_R_CHANNEL_ID_SIGNATURE_INVALID 129
5866 #define SSL_R_CIPHER_OR_HASH_UNAVAILABLE 130
5867 #define SSL_R_CLIENTHELLO_PARSE_FAILED 131
5868 #define SSL_R_CLIENTHELLO_TLSEXT 132
5869 #define SSL_R_CONNECTION_REJECTED 133
5870 #define SSL_R_CONNECTION_TYPE_NOT_SET 134
5871 #define SSL_R_CUSTOM_EXTENSION_ERROR 135
5872 #define SSL_R_DATA_LENGTH_TOO_LONG 136
5873 #define SSL_R_DECODE_ERROR 137
5874 #define SSL_R_DECRYPTION_FAILED 138
5875 #define SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC 139
5876 #define SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG 140
5877 #define SSL_R_DH_P_TOO_LONG 141
5878 #define SSL_R_DIGEST_CHECK_FAILED 142
5879 #define SSL_R_DTLS_MESSAGE_TOO_BIG 143
5880 #define SSL_R_ECC_CERT_NOT_FOR_SIGNING 144
5881 #define SSL_R_EMS_STATE_INCONSISTENT 145
5882 #define SSL_R_ENCRYPTED_LENGTH_TOO_LONG 146
5883 #define SSL_R_ERROR_ADDING_EXTENSION 147
5884 #define SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST 148
5885 #define SSL_R_ERROR_PARSING_EXTENSION 149
5886 #define SSL_R_EXCESSIVE_MESSAGE_SIZE 150
5887 #define SSL_R_EXTRA_DATA_IN_MESSAGE 151
5888 #define SSL_R_FRAGMENT_MISMATCH 152
5889 #define SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION 153
5890 #define SSL_R_HANDSHAKE_FAILURE_ON_CLIENT_HELLO 154
5891 #define SSL_R_HTTPS_PROXY_REQUEST 155
5892 #define SSL_R_HTTP_REQUEST 156
5893 #define SSL_R_INAPPROPRIATE_FALLBACK 157
5894 #define SSL_R_INVALID_COMMAND 158
5895 #define SSL_R_INVALID_MESSAGE 159
5896 #define SSL_R_INVALID_SSL_SESSION 160
5897 #define SSL_R_INVALID_TICKET_KEYS_LENGTH 161
5898 #define SSL_R_LENGTH_MISMATCH 162
5899 #define SSL_R_MISSING_EXTENSION 164
5900 #define SSL_R_MISSING_RSA_CERTIFICATE 165
5901 #define SSL_R_MISSING_TMP_DH_KEY 166
5902 #define SSL_R_MISSING_TMP_ECDH_KEY 167
5903 #define SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS 168
5904 #define SSL_R_MTU_TOO_SMALL 169
5905 #define SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN 170
5906 #define SSL_R_NESTED_GROUP 171
5907 #define SSL_R_NO_CERTIFICATES_RETURNED 172
5908 #define SSL_R_NO_CERTIFICATE_ASSIGNED 173
5909 #define SSL_R_NO_CERTIFICATE_SET 174
5910 #define SSL_R_NO_CIPHERS_AVAILABLE 175
5911 #define SSL_R_NO_CIPHERS_PASSED 176
5912 #define SSL_R_NO_CIPHER_MATCH 177
5913 #define SSL_R_NO_COMPRESSION_SPECIFIED 178
5914 #define SSL_R_NO_METHOD_SPECIFIED 179
5915 #define SSL_R_NO_PRIVATE_KEY_ASSIGNED 181
5916 #define SSL_R_NO_RENEGOTIATION 182
5917 #define SSL_R_NO_REQUIRED_DIGEST 183
5918 #define SSL_R_NO_SHARED_CIPHER 184
5919 #define SSL_R_NULL_SSL_CTX 185
5920 #define SSL_R_NULL_SSL_METHOD_PASSED 186
5921 #define SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED 187
5922 #define SSL_R_OLD_SESSION_VERSION_NOT_RETURNED 188
5923 #define SSL_R_OUTPUT_ALIASES_INPUT 189
5924 #define SSL_R_PARSE_TLSEXT 190
5925 #define SSL_R_PATH_TOO_LONG 191
5926 #define SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE 192
5927 #define SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE 193
5928 #define SSL_R_PROTOCOL_IS_SHUTDOWN 194
5929 #define SSL_R_PSK_IDENTITY_NOT_FOUND 195
5930 #define SSL_R_PSK_NO_CLIENT_CB 196
5931 #define SSL_R_PSK_NO_SERVER_CB 197
5932 #define SSL_R_READ_TIMEOUT_EXPIRED 198
5933 #define SSL_R_RECORD_LENGTH_MISMATCH 199
5934 #define SSL_R_RECORD_TOO_LARGE 200
5935 #define SSL_R_RENEGOTIATION_ENCODING_ERR 201
5936 #define SSL_R_RENEGOTIATION_MISMATCH 202
5937 #define SSL_R_REQUIRED_CIPHER_MISSING 203
5938 #define SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION 204
5939 #define SSL_R_RESUMED_NON_EMS_SESSION_WITH_EMS_EXTENSION 205
5940 #define SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING 206
5941 #define SSL_R_SERVERHELLO_TLSEXT 207
5942 #define SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED 208
5943 #define SSL_R_SESSION_MAY_NOT_BE_CREATED 209
5944 #define SSL_R_SIGNATURE_ALGORITHMS_EXTENSION_SENT_BY_SERVER 210
5945 #define SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES 211
5946 #define SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE 212
5947 #define SSL_R_SSL3_EXT_INVALID_SERVERNAME 213
5948 #define SSL_R_SSL_CTX_HAS_NO_DEFAULT_SSL_VERSION 214
5949 #define SSL_R_SSL_HANDSHAKE_FAILURE 215
5950 #define SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG 216
5951 #define SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST 217
5952 #define SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG 218
5953 #define SSL_R_TOO_MANY_EMPTY_FRAGMENTS 219
5954 #define SSL_R_TOO_MANY_WARNING_ALERTS 220
5955 #define SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS 221
5956 #define SSL_R_UNEXPECTED_EXTENSION 222
5957 #define SSL_R_UNEXPECTED_MESSAGE 223
5958 #define SSL_R_UNEXPECTED_OPERATOR_IN_GROUP 224
5959 #define SSL_R_UNEXPECTED_RECORD 225
5960 #define SSL_R_UNINITIALIZED 226
5961 #define SSL_R_UNKNOWN_ALERT_TYPE 227
5962 #define SSL_R_UNKNOWN_CERTIFICATE_TYPE 228
5963 #define SSL_R_UNKNOWN_CIPHER_RETURNED 229
5964 #define SSL_R_UNKNOWN_CIPHER_TYPE 230
5965 #define SSL_R_UNKNOWN_DIGEST 231
5966 #define SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE 232
5967 #define SSL_R_UNKNOWN_PROTOCOL 233
5968 #define SSL_R_UNKNOWN_SSL_VERSION 234
5969 #define SSL_R_UNKNOWN_STATE 235
5970 #define SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED 236
5971 #define SSL_R_UNSUPPORTED_CIPHER 237
5972 #define SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM 238
5973 #define SSL_R_UNSUPPORTED_ELLIPTIC_CURVE 239
5974 #define SSL_R_UNSUPPORTED_PROTOCOL 240
5975 #define SSL_R_WRONG_CERTIFICATE_TYPE 241
5976 #define SSL_R_WRONG_CIPHER_RETURNED 242
5977 #define SSL_R_WRONG_CURVE 243
5978 #define SSL_R_WRONG_MESSAGE_TYPE 244
5979 #define SSL_R_WRONG_SIGNATURE_TYPE 245
5980 #define SSL_R_WRONG_SSL_VERSION 246
5981 #define SSL_R_WRONG_VERSION_NUMBER 247
5982 #define SSL_R_X509_LIB 248
5983 #define SSL_R_X509_VERIFICATION_SETUP_PROBLEMS 249
5984 #define SSL_R_SHUTDOWN_WHILE_IN_INIT 250
5985 #define SSL_R_INVALID_OUTER_RECORD_TYPE 251
5986 #define SSL_R_UNSUPPORTED_PROTOCOL_FOR_CUSTOM_KEY 252
5987 #define SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS 253
5988 #define SSL_R_DOWNGRADE_DETECTED 254
5989 #define SSL_R_EXCESS_HANDSHAKE_DATA 255
5990 #define SSL_R_INVALID_COMPRESSION_LIST 256
5991 #define SSL_R_DUPLICATE_EXTENSION 257
5992 #define SSL_R_MISSING_KEY_SHARE 258
5993 #define SSL_R_INVALID_ALPN_PROTOCOL 259
5994 #define SSL_R_TOO_MANY_KEY_UPDATES 260
5995 #define SSL_R_BLOCK_CIPHER_PAD_IS_WRONG 261
5996 #define SSL_R_NO_CIPHERS_SPECIFIED 262
5997 #define SSL_R_RENEGOTIATION_EMS_MISMATCH 263
5998 #define SSL_R_DUPLICATE_KEY_SHARE 264
5999 #define SSL_R_NO_GROUPS_SPECIFIED 265
6000 #define SSL_R_NO_SHARED_GROUP 266
6001 #define SSL_R_PRE_SHARED_KEY_MUST_BE_LAST 267
6002 #define SSL_R_OLD_SESSION_PRF_HASH_MISMATCH 268
6003 #define SSL_R_INVALID_SCT_LIST 269
6004 #define SSL_R_TOO_MUCH_SKIPPED_EARLY_DATA 270
6005 #define SSL_R_PSK_IDENTITY_BINDER_COUNT_MISMATCH 271
6006 #define SSL_R_CANNOT_PARSE_LEAF_CERT 272
6007 #define SSL_R_SERVER_CERT_CHANGED 273
6008 #define SSL_R_CERTIFICATE_AND_PRIVATE_KEY_MISMATCH 274
6009 #define SSL_R_CANNOT_HAVE_BOTH_PRIVKEY_AND_METHOD 275
6010 #define SSL_R_TICKET_ENCRYPTION_FAILED 276
6011 #define SSL_R_ALPN_MISMATCH_ON_EARLY_DATA 277
6012 #define SSL_R_WRONG_VERSION_ON_EARLY_DATA 278
6013 #define SSL_R_UNEXPECTED_EXTENSION_ON_EARLY_DATA 279
6014 #define SSL_R_NO_SUPPORTED_VERSIONS_ENABLED 280
6015 #define SSL_R_APPLICATION_DATA_INSTEAD_OF_HANDSHAKE 281
6016 #define SSL_R_EMPTY_HELLO_RETRY_REQUEST 282
6017 #define SSL_R_EARLY_DATA_NOT_IN_USE 283
6018 #define SSL_R_HANDSHAKE_NOT_COMPLETE 284
6019 #define SSL_R_NEGOTIATED_TB_WITHOUT_EMS_OR_RI 285
6020 #define SSL_R_SERVER_ECHOED_INVALID_SESSION_ID 286
6021 #define SSL_R_PRIVATE_KEY_OPERATION_FAILED 287
6022 #define SSL_R_SECOND_SERVERHELLO_VERSION_MISMATCH 288
6023 #define SSL_R_OCSP_CB_ERROR 289
6024 #define SSL_R_SSL_SESSION_ID_TOO_LONG 290
6025 #define SSL_R_APPLICATION_DATA_ON_SHUTDOWN 291
6026 #define SSL_R_CERT_DECOMPRESSION_FAILED 292
6027 #define SSL_R_UNCOMPRESSED_CERT_TOO_LARGE 293
6028 #define SSL_R_UNKNOWN_CERT_COMPRESSION_ALG 294
6029 #define SSL_R_INVALID_SIGNATURE_ALGORITHM 295
6030 #define SSL_R_DUPLICATE_SIGNATURE_ALGORITHM 296
6031 #define SSL_R_TLS13_DOWNGRADE 297
6032 #define SSL_R_QUIC_INTERNAL_ERROR 298
6033 #define SSL_R_WRONG_ENCRYPTION_LEVEL_RECEIVED 299
6034 #define SSL_R_TOO_MUCH_READ_EARLY_DATA 300
6035 #define SSL_R_INVALID_DELEGATED_CREDENTIAL 301
6036 #define SSL_R_KEY_USAGE_BIT_INCORRECT 302
6037 #define SSL_R_INCONSISTENT_CLIENT_HELLO 303
6038 #define SSL_R_CIPHER_MISMATCH_ON_EARLY_DATA 304
6039 #define SSL_R_QUIC_TRANSPORT_PARAMETERS_MISCONFIGURED 305
6040 #define SSL_R_UNEXPECTED_COMPATIBILITY_MODE 306
6041 #define SSL_R_NO_APPLICATION_PROTOCOL 307
6042 #define SSL_R_NEGOTIATED_ALPS_WITHOUT_ALPN 308
6043 #define SSL_R_ALPS_MISMATCH_ON_EARLY_DATA 309
6044 #define SSL_R_ECH_SERVER_CONFIG_AND_PRIVATE_KEY_MISMATCH 310
6045 #define SSL_R_ECH_SERVER_CONFIG_UNSUPPORTED_EXTENSION 311
6046 #define SSL_R_UNSUPPORTED_ECH_SERVER_CONFIG 312
6047 #define SSL_R_ECH_SERVER_WOULD_HAVE_NO_RETRY_CONFIGS 313
6048 #define SSL_R_INVALID_CLIENT_HELLO_INNER 314
6049 #define SSL_R_INVALID_ALPN_PROTOCOL_LIST 315
6050 #define SSL_R_COULD_NOT_PARSE_HINTS 316
6051 #define SSL_R_INVALID_ECH_PUBLIC_NAME 317
6052 #define SSL_R_INVALID_ECH_CONFIG_LIST 318
6053 #define SSL_R_ECH_REJECTED 319
6054 #define SSL_R_INVALID_OUTER_EXTENSION 320
6055 #define SSL_R_INCONSISTENT_ECH_NEGOTIATION 321
6056 #define SSL_R_INVALID_ALPS_CODEPOINT 322
6057 #define SSL_R_SSLV3_ALERT_CLOSE_NOTIFY 1000
6058 #define SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE 1010
6059 #define SSL_R_SSLV3_ALERT_BAD_RECORD_MAC 1020
6060 #define SSL_R_TLSV1_ALERT_DECRYPTION_FAILED 1021
6061 #define SSL_R_TLSV1_ALERT_RECORD_OVERFLOW 1022
6062 #define SSL_R_SSLV3_ALERT_DECOMPRESSION_FAILURE 1030
6063 #define SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE 1040
6064 #define SSL_R_SSLV3_ALERT_NO_CERTIFICATE 1041
6065 #define SSL_R_SSLV3_ALERT_BAD_CERTIFICATE 1042
6066 #define SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE 1043
6067 #define SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED 1044
6068 #define SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED 1045
6069 #define SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN 1046
6070 #define SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER 1047
6071 #define SSL_R_TLSV1_ALERT_UNKNOWN_CA 1048
6072 #define SSL_R_TLSV1_ALERT_ACCESS_DENIED 1049
6073 #define SSL_R_TLSV1_ALERT_DECODE_ERROR 1050
6074 #define SSL_R_TLSV1_ALERT_DECRYPT_ERROR 1051
6075 #define SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION 1060
6076 #define SSL_R_TLSV1_ALERT_PROTOCOL_VERSION 1070
6077 #define SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY 1071
6078 #define SSL_R_TLSV1_ALERT_INTERNAL_ERROR 1080
6079 #define SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK 1086
6080 #define SSL_R_TLSV1_ALERT_USER_CANCELLED 1090
6081 #define SSL_R_TLSV1_ALERT_NO_RENEGOTIATION 1100
6082 #define SSL_R_TLSV1_ALERT_UNSUPPORTED_EXTENSION 1110
6083 #define SSL_R_TLSV1_ALERT_CERTIFICATE_UNOBTAINABLE 1111
6084 #define SSL_R_TLSV1_ALERT_UNRECOGNIZED_NAME 1112
6085 #define SSL_R_TLSV1_ALERT_BAD_CERTIFICATE_STATUS_RESPONSE 1113
6086 #define SSL_R_TLSV1_ALERT_BAD_CERTIFICATE_HASH_VALUE 1114
6087 #define SSL_R_TLSV1_ALERT_UNKNOWN_PSK_IDENTITY 1115
6088 #define SSL_R_TLSV1_ALERT_CERTIFICATE_REQUIRED 1116
6089 #define SSL_R_TLSV1_ALERT_NO_APPLICATION_PROTOCOL 1120
6090 #define SSL_R_TLSV1_ALERT_ECH_REQUIRED 1121
6091 
6092 #endif  // OPENSSL_HEADER_SSL_H
6093